{"id":1393,"date":"2015-09-29T20:26:49","date_gmt":"2015-09-29T20:26:49","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=1393"},"modified":"2024-08-23T12:56:50","modified_gmt":"2024-08-23T12:56:50","slug":"exercicios-de-vestibulares-com-resolucao-comentada-sobre-conservacao-da-quantidade-de-movimento","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/mecanica\/dinamica\/conservacao-da-quantidade-de-movimento\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-conservacao-da-quantidade-de-movimento\/","title":{"rendered":"Conserva\u00e7\u00e3o da Quantidade de Movimento &#8211; Resolu\u00e7\u00e3o"},"content":{"rendered":"<p align=\"CENTER\"><span style=\"color: #c00000;\"><span style=\"font-family: 'Arial Black', serif;\"><span style=\"font-size: large;\"><b>Exerc\u00edcios de vestibulares com resolu\u00e7\u00e3o comentada sobre<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><span style=\"color: #0000cc;\"><span style=\"font-family: 'Arial Black', serif;\"><span style=\"font-size: large;\"><b>Conserva\u00e7\u00e3o da Quantidade de Movimento<\/b><\/span><\/span><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>01-(PUC-RS)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um sistema \u00e9 constitu\u00eddo de duas esferas que se movem sobre um plano horizontal e colidem entre si num determinado instante. Imediatamente ap\u00f3s a colis\u00e3o, pode-se afirmar que, referente ao sistema, permaneceu inalterada a<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) energia cin\u00e9tica. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) energia el\u00e1stica. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) quantidade de movimento. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d)velocidade. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e)energia mec\u00e2nica.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>02-(UFV-MG)<\/b><\/span><\/span><\/span><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um tren\u00f3, com massa total de 250kg, desliza no gelo \u00e0 velocidade de 10 m\/s. Se o o seu condutor atirar para tr\u00e1s<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img fetchpriority=\"high\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_90da1912.jpg\" alt=\"\" width=\"265\" height=\"224\" name=\"graphics6\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>50 kg de carga \u00e0 velocidade de 10m\/s, a nova velocidade do tren\u00f3 ser\u00e1 de:<\/b><\/span><\/span><\/span><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_21359443.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 142\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>03-(Ufsc-PE)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Dois astronautas, A e B, encontram-se livres na parte externa de uma esta\u00e7\u00e3o espacial, sendo desprez\u00edveis as for\u00e7as de atra\u00e7\u00e3o gravitacional sobre eles. Os astronautas com seus trajes espaciais t\u00eam massas m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 100 kg e m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>B<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 90 kg, al\u00e9m de um tanque de oxig\u00eanio transportado\u00a0 pelo\u00a0 astronauta\u00a0 A, de\u00a0 massa 10 kg. Ambos est\u00e3o em repouso em rela\u00e7\u00e3o \u00e0 esta\u00e7\u00e3o espacial, quando o astronauta A lan\u00e7a o tanque de oxig\u00eanio para o astronauta B com uma velocidade de 5,0 m\/s. O tanque choca-se com o astronauta B que o agarra, mantendo-o junto a si, enquanto se afasta.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_44175787.jpg\" alt=\"\" width=\"312\" height=\"119\" name=\"Imagem 7\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considerando como referencial a esta\u00e7\u00e3o espacial, assinale a(s) proposi\u00e7\u00e3o(\u00f5es) CORRETA(S) e anote sua soma:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(01) Considerando que a resultante das for\u00e7as externas \u00e9 nula, podemos afirmar que a quantidade de movimento total do sistema constitu\u00eddo pelos dois astronautas e o tanque se conserva.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(02) Como \u00e9 v\u00e1lida a terceira lei de Newton, o astronauta A, imediatamente ap\u00f3s lan\u00e7ar o tanque para o astronauta B, afasta-se com velocidade igual a 5,0 m\/s.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(04) Antes de o tanque ter sido lan\u00e7ado, a quantidade de movimento total do sistema constitu\u00eddo pelos dois astronautas e o tanque era nula.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(08) Ap\u00f3s o tanque ter sido lan\u00e7ado, a quantidade de movimento do sistema constitu\u00eddo pelos dois astronautas e o tanque permanece nula.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(16) Imediatamente ap\u00f3s agarrar o tanque, o astronauta B passa a deslocar-se com velocidade de m\u00f3dulo igual a 0,5 m\/s.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>04-(Ufjf-MG)<\/b><\/span><\/span><\/span><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um aster\u00f3ide aproxima-se perigosamente da Terra amea\u00e7ando destru\u00ed-la. Sua massa \u00e9 de 10 toneladas e sua velocidade de aproxima\u00e7\u00e3o, em rela\u00e7\u00e3o \u00e0 Terra, \u00e9 de 100 km\/h. Super-Homem \u00e9 ent\u00e3o convocado para salvar o planeta.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_7a02e785.jpg\" alt=\"\" width=\"400\" height=\"163\" name=\"Imagem 8\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Sendo sua massa de 50 kg, qual a velocidade, em rela\u00e7\u00e3o \u00e0 Terra, com que ele deve atingir frontalmente o aster\u00f3ide para que os dois fiquem parados, em rela\u00e7\u00e3o \u00e0 Terra, ap\u00f3s a colis\u00e3o (despreze a atra\u00e7\u00e3o gravitacional da Terra)?<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) 20000 km\/h; \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) 500 km\/h; \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) 250 km\/h; \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) 80 km\/h.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) 12.000 km\/h<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>05-(Uem)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um vag\u00e3o, deslocando-se para a direita com uma velocidade de 10 m\/s, \u00e9 fragmentado por uma explos\u00e3o, em dois peda\u00e7os (1) e (2) de massas iguais, conforme mostra a figura a seguir.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_852ce22.jpg\" alt=\"\" width=\"501\" height=\"107\" name=\"Imagem 9\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Sejam<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_c3407285.jpg\" alt=\"\" width=\"16\" height=\"20\" name=\"Imagem 10\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_f4955305.jpg\" alt=\"\" width=\"14\" height=\"17\" name=\"graphics7\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u201a as velocidades respectivas dos dois fragmentos logo ap\u00f3s a explos\u00e3o e considerando que<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_c3407285.jpg\" alt=\"\" width=\"16\" height=\"20\" name=\"Imagem 12\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_f4955305.jpg\" alt=\"\" width=\"14\" height=\"17\" name=\"Imagem 13\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u201a possuem a mesma dire\u00e7\u00e3o do movimento inicial, assinale, dentre as alternativas a seguir, aquela(s) que poderia(m) corresponder ao(s) movimento(s) de (1) e (2) depois da explos\u00e3o. Anote a soma das verdadeiras:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(01) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 15 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 5 m\/s para a esquerda.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(02) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 20 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 0.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(04) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 30 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 10 m\/s para a esquerda.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(08) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 25 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 0.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(16) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 25 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 5 m\/s para a esquerda.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(32) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 10 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 0.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(64) v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 50 m\/s para a direita e v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 30 m\/s para a esquerda.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>06-(Ufpe)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um casal de patinadores pesando 80 kg e 60 kg, parados um de frente para o outro, empurram-se bruscamente de modo a se movimentarem em sentidos opostos sobre uma superf\u00edcie horizontal sem atrito.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_3cc42fab.png\" alt=\"\" width=\"264\" height=\"169\" name=\"Imagem 143\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Num determinado instante, o patinador mais pesado encontra-se a 12 m do ponto onde os dois se empurraram. Calcule a dist\u00e2ncia, em metros, que separa os dois patinadores neste instante.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>07-(Ufu-MG)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um skatista, sabendo que sua massa \u00e9 de 45 kg, deseja saber a massa de sua irm\u00e3zinha menor. Sendo ele um bom conhecedor das leis da F\u00edsica, realiza o seguinte experimento: ele fica sobre um skate e coloca sua irm\u00e3zinha sentada em outro skate, distante 40 m de sua posi\u00e7\u00e3o, conforme figura a seguir.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_1deaf758.jpg\" alt=\"\" width=\"363\" height=\"117\" name=\"Imagem 15\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma corda muito leve \u00e9 amarrada no skate da irm\u00e3zinha e o skatista exerce um pux\u00e3o na corda, trazendo o skate e a irm\u00e3zinha em sua dire\u00e7\u00e3o, de forma que ambos se encontram a 10 m da posi\u00e7\u00e3o inicial do skatista.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Sabendo-se que cada skate possui massa de 1 kg e, desprezando o peso da corda e o atrito das rodas dos skates com o ch\u00e3o, ap\u00f3s alguns c\u00e1lculos o skatista conclui que a massa de sua irm\u00e3zinha \u00e9 de<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_2f6ee6ce.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 144\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>08-(Ufrrj-RJ)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>FIM DA 2<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>GUERRA MUNDIAL &#8211; BOMBA AT\u00d4MICA<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>SESSENTA ANOS DE TERROR NUCLEAR<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Destru\u00eddas por bombas, Hiroshima e Nagasaki hoje lideram luta contra essas armas<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Domingo, 31 de julho de 2005 &#8211; &#8220;O GLOBO&#8221;<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Gilberto Scofield Jr.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Enviado especial\u00a0 Hiroshima, Jap\u00e3o<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>&#8220;Shizuko Abe tinha 18 anos no dia 6 de agosto de 1945 e, como todos os jovens japoneses durante a Segunda Guerra Mundial, ela havia abandonado os estudos para se dedicar ao esfor\u00e7o de guerra. Era um dia claro e quente de ver\u00e3o e \u00e0s 8h, Shizuko e seus colegas iniciavam a derrubada de parte das casas de madeira do centro de Hiroshima para tentar criar um cord\u00e3o de isolamento antiinc\u00eandio no caso de um bombardeio incendi\u00e1rio a\u00e9reo. \u00c0quela altura, ningu\u00e9m imaginava que Hiroshima seria o laborat\u00f3rio de outro tipo de bombardeio, muito mais devastador e letal, para o qual os abrigos antiinc\u00eandio foram in\u00fateis&#8221;.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>&#8220;Hiroshima, Jap\u00e3o. Passear pelas ruas de Hiroshima hoje &#8211; 60 anos depois da trag\u00e9dia que matou 140 mil pessoas e deixou cicatrizes eternas em outros 60 mil, numa popula\u00e7\u00e3o de 400 mil &#8211; \u00e9 nunca esquecer o passado. Apesar de rica e moderna com seus 1,1 milh\u00e3o de habitantes circulando em bem cuidadas ruas e avenidas, os monumentos \u00e0s v\u00edtimas do terror at\u00f4mico est\u00e3o em todos os lugares&#8221;.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_6dc0753a.jpg\" alt=\"\" width=\"298\" height=\"135\" name=\"Imagem 16\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um exemplo de processo nuclear que pode ocorrer na Natureza \u00e9 aquele em que alguns n\u00facleos at\u00f4micos espontaneamente se desintegram, produzindo um outro n\u00facleo mais leve e uma part\u00edcula chamada part\u00edcula<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a. Consideremos, ent\u00e3o, um modelo representativo desse processo, formado por uma certa part\u00edcula, inicialmente em repouso, que explode, resultando em duas outras part\u00edculas, 1 e 2, de massas M<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 234g e M<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 4g.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Supondo que ap\u00f3s a explos\u00e3o, a part\u00edcula 1 saia com uma velocidade de 1,0 . 10<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>m\/s,<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) determine a velocidade com que sai a part\u00edcula 2, supondo que ela seja freada at\u00e9 o repouso<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) calcule o trabalho realizado para fre\u00e1-la;<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) calcule a intensidade da for\u00e7a necess\u00e1ria para fazer parar a part\u00edcula 2 em uma dist\u00e2ncia de 10m, supondo esta for\u00e7a constante.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>09-(FUVEST-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Num espet\u00e1culo de fogos de artif\u00edcio, um roj\u00e3o, de massa M<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 0,5 kg, ap\u00f3s seu lan\u00e7amento, descreve no c\u00e9u a trajet\u00f3ria indicada na figura. No ponto mais alto de sua trajet\u00f3ria (ponto P), o roj\u00e3o explode, dividindo-se em dois fragmentos, A e B, de massas iguais a M<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\/2. Logo ap\u00f3s a explos\u00e3o, a velocidade horizontal de A, V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, \u00e9 nula, bem como sua velocidade vertical.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_8f438ea1.jpg\" alt=\"\" width=\"365\" height=\"160\" name=\"graphics8\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>NOTE E ADOTE:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A massa do explosivo pode ser considerada desprez\u00edvel.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Determine o intervalo de tempo T<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, em segundos, transcorrido entre o lan\u00e7amento do roj\u00e3o e a explos\u00e3o no ponto P.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Determine a velocidade horizontal V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>B<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, do fragmento B, logo ap\u00f3s a explos\u00e3o, em m\/s.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) Considerando apenas o que ocorre no momento da explos\u00e3o, determine a energia E<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>0<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>fornecida pelo explosivo aos dois fragmentos A e B, em joules.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>10-(Ufjf-MG)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um avi\u00e3o bombardeiro, voando em linha reta com uma velocidade V na horizontal, solta uma bomba que se fragmenta em duas partes em algum instante antes de tocar o solo. Sabendo-se que a massa total da bomba \u00e9 M e que um dos fragmentos fica com massa (1\/3)M e a outra (2\/3)M, se os fragmentos tocam o solo simultaneamente, qual a raz\u00e3o entre as dist\u00e2ncias horizontais do fragmento menor e do fragmento maior, quando as mesmas tocam o solo, em rela\u00e7\u00e3o \u00e0 posi\u00e7\u00e3o do avi\u00e3o na dire\u00e7\u00e3o horizontal? Despreze a resist\u00eancia do ar e considere que a topografia do local seja totalmente plana.<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_b54eca8e.png\" alt=\"\" width=\"775\" height=\"18\" name=\"Imagem 145\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>11-(Ufrj-RJ)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A figura a seguir representa, uma jangada de comprimento L, em repouso, flutuando em alto mar com o pescador de p\u00e9, equidistante das extremidades. Por inadvert\u00eancia, ele havia levado a jangada para um local onde a Marinha de Guerra estava realizando exerc\u00edcios de tiro. Assim, em determinado instante, ele percebe um torpedo que se desloca numa dire\u00e7\u00e3o perpendicular \u00e0 do comprimento da jangada e que ir\u00e1 atingi-la muito pr\u00f3ximo de uma de suas extremidades.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4d6bf87d.jpg\" alt=\"\" width=\"308\" height=\"130\" name=\"Imagem 18\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Para tentar evitar que a jangada seja atingida, o pescador deve correr ao longo da dire\u00e7\u00e3o AB, aproximando-se de A ou de B? Justifique sua resposta.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>12-(UNIFESP-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um pescador est\u00e1 em um barco em repouso em um lago de \u00e1guas tranq\u00fcilas. A massa do pescador \u00e9 de 70 kg; a massa do barco e demais equipamentos nele contidos \u00e9 de 180 kg.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Suponha que o pescador esteja em p\u00e9 e d\u00ea um passo para a proa (dianteira do barco). O que acontece com o barco? Justifique.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(Desconsidere poss\u00edveis movimentos oscilat\u00f3rios e o atrito viscoso entre o barco e a \u00e1gua.)<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Em um determinado instante, com o barco em repouso em rela\u00e7\u00e3o \u00e0 \u00e1gua, o pescador resolve deslocar seu barco para frente com uma \u00fanica remada. Suponha que o m\u00f3dulo da for\u00e7a m\u00e9dia exercida pelos remos sobre a \u00e1gua, para tr\u00e1s, seja de 250 N e o intervalo de tempo em que os remos interagem com a \u00e1gua seja de 2,0 segundos.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Admitindo desprez\u00edvel o atrito entre o barco e a \u00e1gua, qual a velocidade do barco em rela\u00e7\u00e3o \u00e0 \u00e1gua ao final desses 2,0 s?<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>13-(UFSC)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Na situa\u00e7\u00e3o apresentada na figura a seguir desconsidere o efeito do atrito.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Estando todas as partes em repouso no in\u00edcio, uma pessoa puxa com sua m\u00e3o uma corda que est\u00e1 amarrada ao outro barco. Considere que o barco vazio (B) tenha a metade da massa do\u00a0 barco mais a pessoa que formam o conjunto (A).<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_181c7833.jpg\" alt=\"\" width=\"369\" height=\"112\" name=\"Imagem 19\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Assinale a(s) proposi\u00e7\u00e3o(\u00f5es) CORRETA(S) e anote sua soma.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(01) Ap\u00f3s a pessoa puxar a corda, ambos os barcos se mover\u00e3o com a mesma velocidade.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(02) Ap\u00f3s o puxar da corda, o m\u00f3dulo da velocidade de B ser\u00e1 o dobro do m\u00f3dulo da velocidade de A.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(04) \u00c9 imposs\u00edvel fazer qualquer afirma\u00e7\u00e3o sobre as velocidades das partes do sistema ao se iniciar o movimento.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(08) Ap\u00f3s o puxar da corda, as quantidades de movimento dos barcos apresentar\u00e3o depend\u00eancia entre si.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(16) Ao se iniciar o movimento, a energia cin\u00e9tica de A \u00e9 sempre igual \u00e0 energia cin\u00e9tica de B.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>14-(Ufu-MG)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um garoto brinca com seu barquinho de papel, que tem uma massa igual a 30 g e est\u00e1 navegando sobre um pequeno lago. Em certo instante, ele coloca sobre o barquinho, sem toc\u00e1-lo, uma bolinha de isopor e percebe que o barquinho passa a andar com metade de sua velocidade inicial. Seu irm\u00e3o mais velho, que observa a brincadeira, resolve estimar a massa da bolinha de isopor com base na varia\u00e7\u00e3o da velocidade do barquinho. Desprezando efeitos relativos ao empuxo, ele conclui que a massa da bolinha \u00e9 de<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_3661824d.png\" alt=\"\" width=\"774\" height=\"21\" name=\"Imagem 146\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>15- (Ufu-MG)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Jo\u00e3o, em um ato de gentileza, empurra uma poltrona para Maria, que a espera em repouso num segundo plano horizontal (0,8 m abaixo do plano de Jo\u00e3o). A poltrona tem uma massa de 10 kg e Maria tem uma massa de 50 kg. O ch\u00e3o \u00e9 t\u00e3o liso que todos os atritos podem ser desprezados, conforme figura 1.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A poltrona \u00e9 empurrada de A at\u00e9 B, partindo do repouso em A. Jo\u00e3o exerce uma for\u00e7a constante igual a 25 N, na dire\u00e7\u00e3o horizontal. Em B a poltrona \u00e9 solta, descendo a pequena rampa de 0,8 m de altura. Quando a poltrona chega com uma certa velocidade (v) em Maria, ela senta-se rapidamente na poltrona, sem exercer qualquer for\u00e7a horizontal sobre ela, e o sistema poltrona + Maria escorrega no segundo plano horizontal, conforme figura 2.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4fa78808.jpg\" alt=\"\" width=\"727\" height=\"98\" name=\"Imagem 20\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considerando a acelera\u00e7\u00e3o da gravidade como 10 m\/s<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, calcule:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) o trabalho realizado por Jo\u00e3o no percurso AB.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) a velocidade (v) da poltrona ao chegar em Maria.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) a velocidade do sistema poltrona + Maria, ap\u00f3s Maria sentar-se na poltrona.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>16-(PUC-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um tronco de massa 50kg desce um rio levado pela correnteza com velocidade constante de 2,0m\/s. Uma ave de massa 10kg, voando a 2,0m\/s, rio acima, procura pousar sobre o tronco. A ave escorrega de uma extremidade a outra sem conseguir permanecer sobre o tronco, saindo com velocidade de 0,5m\/s. Desprezando a resist\u00eancia da \u00e1gua, qual a velocidade do tronco, assim que a ave o abandona?<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_8da8540.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 147\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>17-(Ufjf-MG)<\/b><\/span><\/span><\/span><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Quando se abre uma torneira de forma que saia apenas um &#8220;filete&#8221; de \u00e1gua, a \u00e1rea da se\u00e7\u00e3o reta do filete de \u00e1gua<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_34d65bb5.jpg\" alt=\"\" width=\"134\" height=\"158\" name=\"Imagem 22\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>abaixo da boca da torneira \u00e9 tanto menor quanto mais distante dela, porque:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) como a velocidade da \u00e1gua distante da boca da torneira \u00e9 maior devido \u00e0 a\u00e7\u00e3o da for\u00e7a gravitacional, para que haja conserva\u00e7\u00e3o da massa, a \u00e1rea da se\u00e7\u00e3o reta do filete tem que ser menor.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) uma vez que a velocidade da \u00e1gua distante da boca da torneira \u00e9 menor devido \u00e0 a\u00e7\u00e3o da for\u00e7a gravitacional, para que haja conserva\u00e7\u00e3o da massa, a \u00e1rea da se\u00e7\u00e3o reta do filete tem que ser menor.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) a velocidade da \u00e1gua caindo n\u00e3o depende da for\u00e7a gravitacional e, portanto, para que haja conserva\u00e7\u00e3o da massa, a \u00e1rea da se\u00e7\u00e3o reta do filete tem que ser menor.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) as intera\u00e7\u00f5es entre as mol\u00e9culas da \u00e1gua tornam-se mais intensas devido \u00e0 a\u00e7\u00e3o da for\u00e7a gravitacional e, assim, a \u00e1rea da se\u00e7\u00e3o reta do filete distante da boca da torneira fica menor.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) devido \u00e0 velocidade com que a \u00e1gua sai, a boca da torneira \u00e9 projetada para que a \u00e1gua seja concentrada mais distante da boca.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>18-(ITA-SP)<\/b><\/span><\/span><\/span><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Todo ca\u00e7ador, ao atirar com um rifle, mant\u00e9m a arma firmemente apertada contra o ombro evitando assim o &#8220;coice&#8221; da mesma. Considere que a massa do atirador \u00e9 95,0 kg, a massa do rifle \u00e9 5,00 kg e a massa do proj\u00e9til \u00e9 15,0 g\u00a0 a qual \u00e9 disparada a uma velocidade de 3,00 \u00d7 10<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>m\/s. Nestas condi\u00e7\u00f5es,\u00a0 determine a velocidade de recuo do rifle (Vr) quando se segura muito frouxamente a arma e a velocidade de recuo do atirador (Va) quando ele mant\u00e9m a arma firmemente apoiada no ombro.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>19- (UNICAMP-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Imagine a seguinte situa\u00e7\u00e3o: um d\u00e1lmata corre e pula para dentro de um pequeno tren\u00f3, at\u00e9 ent\u00e3o parado, caindo nos bra\u00e7os de sua dona. Em consequ\u00eancia, o tren\u00f3 come\u00e7a a se movimentar.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considere os seguintes dados:\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I. a massa do cachorro \u00e9 de 10kg;<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>II. a massa do conjunto tren\u00f3 + mo\u00e7a \u00e9 de 90kg;<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>III. a velocidade horizontal do cachorro imediatamente antes de ser seguro por sua dona \u00e9 de 18km\/h.\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Desprezando-se o atrito entre o tren\u00f3 e o gelo, determine a velocidade horizontal do sistema tren\u00f3 + mo\u00e7a + cachorro, imediatamente ap\u00f3s o cachorro ter ca\u00eddo nos bra\u00e7os de sua dona.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Determine a varia\u00e7\u00e3o de energia cin\u00e9tica no processo.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>20-(UnB-DF)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Aprende-se em aulas de educa\u00e7\u00e3o f\u00edsica que, ao se saltar, \u00e9 fundamental flexionar as pernas para amenizar o impacto no solo e evitar danos \u00e0 coluna vertebral, que possui certo grau de flexibilidade. No caso de uma queda em p\u00e9, com as pernas esticadas, uma pessoa pode chegar a ter, no estado de maior compress\u00e3o da coluna, a sua altura diminu\u00edda em at\u00e9 3 cm. Nesse caso, o esqueleto da pessoa, com a velocidade adquirida durante a queda, desacelera bruscamente no espa\u00e7o m\u00e1ximo de 3 cm. Supondo que uma pessoa de 70 kg caia de um degrau de 0,5 m de altura, atingindo o solo em p\u00e9, com as pernas esticadas e recebendo todo o impacto diretamente sobre o calcanhar e a coluna, julgue os itens seguintes.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(1) No instante em que a pessoa deixa o degrau, a varia\u00e7\u00e3o do seu momento linear \u00e9 produzida pela for\u00e7a peso.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(2) Durante o impacto, a for\u00e7a de compress\u00e3o m\u00e9dia a que a coluna est\u00e1 sujeita \u00e9 momentaneamente superior ao peso correspondente \u00e0 massa de 1 tonelada.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(3) Em m\u00f3dulo, a for\u00e7a de compress\u00e3o da coluna \u00e9 igual \u00e0 for\u00e7a que o solo exerce nos p\u00e9s da pessoa.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>(4) Se flexionasse as pernas, a pessoa aumentaria o espa\u00e7o de desacelera\u00e7\u00e3o, diminuindo, portanto, o impacto do choque com o solo.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>21-(FUVEST-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um objeto A de massa M=4,0kg, \u00e9 largado da janela de um edif\u00edcio, de uma altura H<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=45m. Procurando diminuir o impacto de A com o ch\u00e3o, um objeto B, de mesma massa, \u00e9 lan\u00e7ado um pouco depois, a partir do ch\u00e3o, verticalmente, com velocidade inicial V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>oB<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. Os dois objetos colidem a uma altura de 25m, com velocidades de mesmo m\u00f3dulo. Com o impacto, grudam-se ambos, um no outro, formando um s\u00f3 corpo AB, de massa 2M, que cai atingindo o ch\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_50403611.jpg\" alt=\"\" width=\"194\" height=\"216\" name=\"Imagem 23\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Determine a energia mec\u00e2nica Q, em joules, dissipada na colis\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Determine a energia cin\u00e9tica Ec, em joules, imediatamente antes de AB atingir o solo.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>22-(UnB-DF)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 <\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Novos sistemas de propuls\u00e3o de foguetes\u00a0 e de sondas espaciais est\u00e3o sempre sendo estudados pela Nasa. \u00a0Um dos projetos utiliza o princ\u00edpio de atirar e receber bolas de metal para ganhar impulso. O sistema funcionaria da seguinte forma: em uma esta\u00e7\u00e3o espacial, um disco girando, atiraria bolas met\u00e1licas a uma velocidade de 7.200km\/h. Uma sonda espacial as receberia e as mandaria de volta ao disco da esta\u00e7\u00e3o. Segundo pesquisadores esse sistema de receber e atirar bolas de metal poderia ser usado para dar o impulso inicial a naves ou sondas espaciais que j\u00e1 estivessem em \u00f3rbita. (Folha de S\u00e3o Paulo,13\/12\/1988:com adapta\u00e7\u00f5es)<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_19b5e5c.jpg\" alt=\"\" width=\"473\" height=\"159\" name=\"Imagem 24\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considere uma sonda espacial com massa de 1 tonelada, em repouso em rela\u00e7\u00e3o a uma esta\u00e7\u00e3o espacial, conforme a figura acima.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Suponha que a sonda receba, pela entrada E, uma bola de 10kg, atirada a 2.000m\/s pelo disco da esta\u00e7\u00e3o e a devolva, pela sa\u00edda S, com um quinto do m\u00f3dulo da velocidade inicial. Calcule, em m\/s,\u00a0 o m\u00f3dulo da velocidade da sonda em rela\u00e7\u00e3o \u00e0 esta\u00e7\u00e3o no instante em que a bola \u00e9 devolvida. Despreze a parte fracion\u00e1ria do resultado, caso exista.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>23-(FUVEST-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um aster\u00f3ide, no espa\u00e7o, est\u00e1 em repouso em rela\u00e7\u00e3o a um determinado referencial. Num certo instante ele explode\u00a0 em tr\u00eas fragmentos. Dentre os esquemas representados, assinale o \u00fanico que pode representar os vetores velocidades dos fragmentos do aster\u00f3ide logo ap\u00f3s a explos\u00e3o, em rela\u00e7\u00e3o ao referencial inicial.<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_8dd893c9.jpg\" alt=\"\" width=\"160\" height=\"91\" name=\"Imagem 25\" align=\"BOTTOM\" border=\"0\" \/><span style=\"color: #000000;\">\u00a0\u00a0<\/span><span style=\"color: #000000;\">\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_5de66e1d.jpg\" alt=\"\" width=\"112\" height=\"80\" name=\"Imagem 26\" align=\"BOTTOM\" border=\"0\" \/><\/span><span style=\"color: #000000;\">\u00a0\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_b70ff692.jpg\" alt=\"\" width=\"140\" height=\"78\" name=\"Imagem 27\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_e3281ea3.jpg\" alt=\"\" width=\"136\" height=\"101\" name=\"Imagem 28\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_acc63640.jpg\" alt=\"\" width=\"117\" height=\"114\" name=\"Imagem 29\" align=\"BOTTOM\" border=\"0\" \/><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>24-(UFSCAR-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma granada est\u00e1 em repouso sobre um plano horizontal sem atrito. Ela explode em tr\u00eas peda\u00e7os de massas m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. Ap\u00f3s a explos\u00e3o, que se deu no ponto D, o peda\u00e7o de massa m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>se movimenta na dire\u00e7\u00e3o e sentido do eixo X com velocidade<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_bf4ecd07.jpg\" alt=\"\" width=\"13\" height=\"18\" name=\"Imagem 30\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, enquanto o peda\u00e7o de massa m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>se movimenta com velocidade<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_899f8f07.jpg\" alt=\"\" width=\"18\" height=\"21\" name=\"Imagem 31\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0na dire\u00e7\u00e3o e sentido do eixo Y.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_9c93e065.jpg\" alt=\"\" width=\"217\" height=\"196\" name=\"Imagem 32\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Sabendo que m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e que V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, qual das setas pode indicar a dire\u00e7\u00e3o e o sentido do movimento de m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>imediatamente ap\u00f3s a explos\u00e3o?<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>25-(Ufpb)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>H\u00e1 60 anos, lamentavelmente, foi lan\u00e7ada, sobre Hiroshima, uma bomba at\u00f4mica cujo princ\u00edpio f\u00edsico \u00e9 o da fiss\u00e3o nuclear. Nesse processo, um n\u00facleo at\u00f4mico pesado divide-se em n\u00facleos menores, liberando grande quantidade de energia em todas as dire\u00e7\u00f5es. Suponha que o n\u00facleo de um determinado \u00e1tomo parte-se em tr\u00eas peda\u00e7os de mesma massa, movendo-se com velocidades iguais em m\u00f3dulo (v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= v), nas dire\u00e7\u00f5es indicadas na figura.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considere a massa total, ap\u00f3s a divis\u00e3o, igual \u00e0 massa inicial.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_35c73293.jpg\" alt=\"\" width=\"284\" height=\"180\" name=\"Imagem 33\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A velocidade v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>i<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>do n\u00facleo, antes da divis\u00e3o, \u00e9:<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_1aadbbaa.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 148\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>26- (PUC-PR)<\/b><\/span><\/span><\/span><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma granada \u00e9 lan\u00e7ada verticalmente com uma velocidade V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. Decorrido um tempo, sua velocidade \u00e9 V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\/2 para cima, quando ocorre a explos\u00e3o. A granada fragmenta-se em quatro peda\u00e7os, de mesma massa, cujas velocidades imediatamente ap\u00f3s a explos\u00e3o s\u00e3o apresentadas na figura.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4c8d96e8.jpg\" alt=\"\" width=\"231\" height=\"161\" name=\"Imagem 34\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considerando a conserva\u00e7\u00e3o da quantidade de movimento, e, dentre as alternativas poss\u00edveis que relacionam o m\u00f3dulo da velocidade, assinale a \u00fanica correta:<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_eb3e9589.jpg\" alt=\"\" width=\"767\" height=\"27\" name=\"Imagem 35\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>27-(INATEL-MG)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma explos\u00e3o divide um peda\u00e7o de rocha em tr\u00eas partes de massas m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=20kg e m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=40kg. As partes m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>s\u00e3o lan\u00e7adas a uma velocidade de 20m\/s, conforme as orienta\u00e7\u00f5es indicadas na figura abaixo.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_9e0082f3.jpg\" alt=\"\" width=\"309\" height=\"168\" name=\"Imagem 36\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considerando o sistema isolado de for\u00e7as externas, calcula-se que o m\u00f3dulo da velocidade da parte m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00e9 V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=10m\/s, com a seguinte orienta\u00e7\u00e3o:<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_89764b39.jpg\" alt=\"\" width=\"234\" height=\"147\" name=\"graphics9\" align=\"BOTTOM\" border=\"0\" \/><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><span style=\"color: #000000;\">\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_67538038.jpg\" alt=\"\" width=\"225\" height=\"158\" name=\"Imagem 38\" align=\"BOTTOM\" border=\"0\" \/><\/span><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><span style=\"color: #000000;\">\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_e89432dd.jpg\" alt=\"\" width=\"180\" height=\"210\" name=\"Imagem 39\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_58606f16.jpg\" alt=\"\" width=\"231\" height=\"181\" name=\"Imagem 40\" align=\"BOTTOM\" border=\"0\" \/><\/span><span style=\"color: #000000;\">\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><span style=\"color: #000000;\">\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_5e4c9e9e.jpg\" alt=\"\" width=\"226\" height=\"189\" name=\"Imagem 41\" align=\"BOTTOM\" border=\"0\" \/><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>28-(UNICAMP-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A exist\u00eancia do neutrino e do antineutrino foi proposta em 1930 por Wolfang Pauli, que aplicou as leis da conserva\u00e7\u00e3o de quantidade de movimento e energia ao processo de desintegra\u00e7\u00e3o<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b. O esquema abaixo ilustra esse processo para um n\u00facleo de tr\u00edtio, H<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, (um is\u00f3topo do hidrog\u00eanio), que se transforma em um n\u00facleo de h\u00e9lio, He<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>3<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, mais um eletron e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>&#8211;<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, e um antineutrino,<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_41fe09a1.jpg\" alt=\"\" width=\"12\" height=\"18\" name=\"Imagem 42\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. O n\u00facleo de tr\u00edtio encontra-se inicialmente em repouso. Ap\u00f3s a desintegra\u00e7\u00e3o, o n\u00facleo de H\u00e9lio possui uma quantidade de movimento com m\u00f3dulo de 12.10<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>-24<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>kg.m\/s e o el\u00e9tron sai em uma trajet\u00f3ria fazendo um \u00e2ngulo de 60<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>com o eixo horizontal e uma quantidade de movimento de m\u00f3dulo 6,0.10<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>-24<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>kg.m\/s.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_dc971da1.jpg\" alt=\"\" width=\"313\" height=\"164\" name=\"Imagem 43\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) O \u00e2ngulo<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>que a trajet\u00f3ria do neutrino\u00a0 faz com o eixo horizontal \u00e9 de 30<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. Determine o m\u00f3dulo da quantidade de movimento do antineutrino.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Qual \u00e9 a velocidade do n\u00facleo de h\u00e9lio p\u00f3s a desintegra\u00e7\u00e3o? A massa do n\u00facleo de h\u00e9lio \u00e9 5,0.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>10<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>-27<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>kg.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>29-(UNICAMP-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma bomba explode em tr\u00eas fragmentos na forma mostrada na figura a seguir.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_b447d510.jpg\" alt=\"\" width=\"348\" height=\"171\" name=\"Imagem 44\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Ache v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>em termos de v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Ache v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>em termos de v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) A energia mec\u00e2nica aumenta, diminui ou permanece a mesma? Justifique.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>30-(FUVEST-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um corpo de 6,0 kg, deslocando-se com velocidade<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4f74301c.jpg\" alt=\"\" width=\"16\" height=\"15\" name=\"graphics10\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0na dire\u00e7\u00e3o e sentido de um eixo x e livre de for\u00e7as externas, explode, separando-se em dois peda\u00e7os, A e B, de massas mA e mB, respectivamente. Ap\u00f3s a explos\u00e3o, A e B passam a se deslocar no plano xOy, afastando-se do ponto O com velocidades<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_dfe0a789.jpg\" alt=\"\" width=\"16\" height=\"20\" name=\"graphics11\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_9f0bc4df.jpg\" alt=\"\" width=\"18\" height=\"21\" name=\"graphics12\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, respectivamente, segundo as dire\u00e7\u00f5es representadas esquematicamente por linhas pontilhadas na figura<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_d22ad996.jpg\" alt=\"\" width=\"304\" height=\"152\" name=\"Imagem 48\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Sendo v o m\u00f3dulo de<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4f74301c.jpg\" alt=\"\" width=\"16\" height=\"15\" name=\"Imagem 49\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e sabendo que os m\u00f3dulos das componentes vetoriais de<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_dfe0a789.jpg\" alt=\"\" width=\"16\" height=\"20\" name=\"Imagem 50\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_9f0bc4df.jpg\" alt=\"\" width=\"18\" height=\"21\" name=\"Imagem 51\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0na dire\u00e7\u00e3o de x valem, respectivamente, V\/2 e 2V, determine as massas m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>B<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) Sendo V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>AY<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>BY<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, respectivamente, os m\u00f3dulos das componentes de<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_dfe0a789.jpg\" alt=\"\" width=\"16\" height=\"20\" name=\"Imagem 52\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_9f0bc4df.jpg\" alt=\"\" width=\"18\" height=\"21\" name=\"Imagem 53\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0na dire\u00e7\u00e3o de y, determine a raz\u00e3o V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\/V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>B<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>31-(UNICAMP-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b> O lixo espacial \u00e9 composto por partes de naves espaciais e sat\u00e9lites fora de opera\u00e7\u00e3o abandonados em \u00f3rbita ao redor da Terra. Esses objetos podem colidir com sat\u00e9lites, al\u00e9m de p\u00f4r em risco astronautas em atividades extraveiculares. Considere que durante um reparo na esta\u00e7\u00e3o espacial, um astronauta substitui um painel solar, de massa m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>p<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 80<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_c2306f5a.jpg\" alt=\"\" width=\"249\" height=\"175\" name=\"Imagem 54\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>kg, cuja estrutura foi danificada. O astronauta estava inicialmente em repouso em rela\u00e7\u00e3o \u00e0 esta\u00e7\u00e3o e ao abandonar o painel no espa\u00e7o, lan\u00e7a-o com uma velocidade v<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>p<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 0,15 m\/s.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) Sabendo que a massa do astronauta \u00e9 m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 60 kg, calcule sua velocidade de recuo.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) O gr\u00e1fico a seguir mostra, de forma simplificada, o m\u00f3dulo da for\u00e7a aplicada pelo astronauta sobre o painel em fun\u00e7\u00e3o do<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_ec5c92ca.jpg\" alt=\"\" width=\"345\" height=\"187\" name=\"Imagem 55\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>tempo durante o lan\u00e7amento. Sabendo que a varia\u00e7\u00e3o de momento linear \u00e9 igual ao impulso, cujo m\u00f3dulo pode ser obtido pela \u00e1rea do gr\u00e1fico, calcule a for\u00e7a m\u00e1xima\u00a0 F<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>max<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>32-(UFSC-SC)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 Dois patinadores, um homem e um menino, de massas respectivamente iguais a 60 kg e 30 kg, est\u00e3o em p\u00e9, de frente um para o outro, em repouso, sobre uma superf\u00edcie de gelo, lisa, plana e horizontal. Quando um empurra o outro, o homem adquire uma velocidade de 0,3 m\/s em rela\u00e7\u00e3o ao gelo.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_72cad0a8.jpg\" alt=\"\" width=\"288\" height=\"169\" name=\"Imagem 56\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Considerando desprez\u00edvel o atrito entre os patins dos patinadores e o gelo, assinale a(s) proposi\u00e7\u00e3o(\u00f5es) CORRETA(S).<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>01) A dist\u00e2ncia entre os patinadores 2,0 s ap\u00f3s eles se separarem \u00e9 de 1,8 m. \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>02) A energia mec\u00e2nica do sistema homem-menino se conserva. \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>04) As for\u00e7as que o homem e o menino fazem um sobre o outro s\u00e3o conservativas.<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>08) A for\u00e7a externa resultante sobre o sistema homem-menino \u00e9 nula.<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>16) Como a massa do homem \u00e9 maior do que a do menino, a quantidade de movimento do sistema tem o mesmo sentido que a quantidade de movimento do homem.<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>32) As for\u00e7as internas que atuam no sistema homem-menino n\u00e3o alteram a quantidade de movimento total do sistema.\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>33-(FUVEST-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 A part\u00edcula neutra conhecida como m\u00e9son K<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00e9 inst\u00e1vel e decai, emitindo duas part\u00edculas, com massas iguais, uma positiva e outra negativa, chamadas, respectivamente, m\u00e9son<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4682ce77.jpg\" alt=\"\" width=\"16\" height=\"14\" name=\"graphics13\" align=\"BOTTOM\" border=\"0\" \/>\u00a0e m\u00e9son<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_e698f73a.jpg\" alt=\"\" width=\"18\" height=\"15\" name=\"Imagem 58\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. Em um experimento, foi observado o<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_50799564.jpg\" alt=\"\" width=\"337\" height=\"107\" name=\"Imagem 59\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>decaimento de um K<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, em repouso, com emiss\u00e3o do par<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4682ce77.jpg\" alt=\"\" width=\"16\" height=\"14\" name=\"Imagem 60\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_e698f73a.jpg\" alt=\"\" width=\"18\" height=\"15\" name=\"Imagem 61\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>. Das figuras a seguir, qual poderia representar as dire\u00e7\u00f5es e sentidos das velocidades das part\u00edculas<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_4682ce77.jpg\" alt=\"\" width=\"16\" height=\"14\" name=\"Imagem 62\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_e698f73a.jpg\" alt=\"\" width=\"18\" height=\"15\" name=\"graphics14\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>no sistema de refer\u00eancia em que o K<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>estava em repouso?<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_db5004e4.jpg\" alt=\"\" width=\"754\" height=\"122\" name=\"Imagem 64\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>34-(ITA-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 Uma massa m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>1<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>com velocidade inicial V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>colide com um sistema massa-mola m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e constante el\u00e1stica k, inicialmente em repouso sobre uma superf\u00edcie sem atrito, conforme ilustra a figura.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_8f3251b6.jpg\" alt=\"\" width=\"384\" height=\"110\" name=\"Imagem 65\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Determine o m\u00e1ximo comprimento de compress\u00e3o da mola, considerando desprez\u00edvel a sua massa.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>35-(UFG-GO)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 Um arqueiro est\u00e1 posicionado a determinada dist\u00e2ncia do ponto P, de onde um alvo \u00e9 lan\u00e7ado do solo ver\u00adticalmente e alcan\u00e7a a altura m\u00e1xima H = 20 m. Flechas s\u00e3o lan\u00e7adas de uma altura igual a h<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>o<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 2,0 m com velocidade de m\u00f3dulo de 21 m\/s. Em uma de suas tentativas, o arqueiro acerta o alvo no instante em que tanto a flecha quanto o alvo encontram-se na posi\u00e7\u00e3o mais alta de suas trajet\u00f3rias, conforme ilustra a figu\u00adra.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_c9a96a22.jpg\" alt=\"\" width=\"467\" height=\"196\" name=\"Imagem 66\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Sabendo que a massa do alvo \u00e9 cinco vezes a da flecha e desprezando as perdas de energia por atrito, calcule:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) a velocidade do conjunto flecha-alvo imediatamente ap\u00f3s a colis\u00e3o;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) a dist\u00e2ncia L, considerando o fato de que a flecha e o alvo chegam solid\u00e1rios ao solo.\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>36-(PUC-RS)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 Em uma rodovi\u00e1ria, um funcion\u00e1rio joga uma mala de 20,0 kg com velocidade<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_16be59ba.jpg\" alt=\"\" width=\"397\" height=\"185\" name=\"Imagem 67\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>horizontal de 4,00 m\/s, sobre um carrinho de 60,0 kg, que estava parado. O carrinho pode mover-se livremente sem atrito; al\u00e9m disso, a resist\u00eancia do ar \u00e9 desprezada. Considerando que a mala escorrega sobre o carrinho e para, \u00e9 correto afirmar que, nessa colis\u00e3o entre a mala e o carrinho, o m\u00f3dulo da velocidade horizontal adquirida pelo sistema carrinho-mala \u00e9 ____________ e a energia mec\u00e2nica do sistema __________________.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>As express\u00f5es que completam correta e respectivamente as lacunas s\u00e3o:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) 1,33m\/s; permanece a mesma\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) 1,33m\/s; diminui\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) 1,00m\/s; diminui\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) 1,00m\/s; aumenta\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) 4,00m\/s; permanece a mesma\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>37-(FUVEST-SP)<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b> Um gavi\u00e3o avista, abaixo dele, um melro e, para apanh\u00e1-lo, passa a voar<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_8d19ed20.jpg\" alt=\"\" width=\"456\" height=\"170\" name=\"Imagem 68\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>verticalmente, conseguindo agarr\u00e1-lo. Imediatamente antes do instante em que o gavi\u00e3o, de massa M<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>G<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 300 g, agarra o melro, de massa M<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>M<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 100 g, as velocidades do gavi\u00e3o e do melro s\u00e3o, respectivamente, V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>G<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 80 km\/h na dire\u00e7\u00e3o vertical, para baixo, e V<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>M<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 24 km\/h na dire\u00e7\u00e3o horizontal, para a direita, como ilustra a figura acima. Imediatamente ap\u00f3s a ca\u00e7a, o vetor velocidade u do gavi\u00e3o, que voa segurando o melro, forma um \u00e2ngulo \u03b1 com o plano horizontal tal que tg \u03b1 \u00e9 aproximadamente igual a<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_6aaac689.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 149\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #c00000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>38-(UNICAMP-SP)<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_af083396.jpg\" alt=\"\" width=\"624\" height=\"120\" name=\"Imagem 69\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>O tempo de viagem de qualquer entrada da Unicamp at\u00e9 a regi\u00e3o central do campus \u00e9 de apenas alguns minutos.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_1f2757a2.jpg\" alt=\"\" width=\"580\" height=\"113\" name=\"Imagem 70\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Assim,\u00a0 a economia de tempo obtida, desrespeitando-se o limite de velocidade, \u00e9\u00a0 muito pequena, enquanto o risco de acidentes aumenta significativamente.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a)\u00a0 Considere que um \u00f4nibus de massa M = 9000 kg , viajando a 80 km\/h,\u00a0 colide\u00a0 na traseira de um carro de massa\u00a0 m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=1000 kg<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_f90062db.jpg\" alt=\"\" width=\"462\" height=\"105\" name=\"Imagem 71\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>que se encontrava parado. A colis\u00e3o \u00e9\u00a0 inel\u00e1stica, ou seja, carro e \u00f4nibus seguem grudados ap\u00f3s a batida.\u00a0 Calcule a\u00a0 velocidade do<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>conjunto logo ap\u00f3s a colis\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b)\u00a0 Al\u00e9m do excesso de velocidade, a falta de manuten\u00e7\u00e3o do ve\u00edculo pode causar acidentes. Por exemplo, o\u00a0 desalinhamento das rodas faz com que o carro sofra a a\u00e7\u00e3o de uma for\u00e7a lateral. Considere um carro com um pneu dianteiro desalinhado de 3\u00b0,<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>conforme\u00a0 a figura abaixo, gerando uma componente lateral da for\u00e7a de atrito<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_31628bf6.jpg\" alt=\"\" width=\"12\" height=\"21\" name=\"Imagem 72\" align=\"BOTTOM\" border=\"0\" \/><\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>em uma das rodas.\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/conservacao\/i_2388133f1bc43cbc_html_25193ad4.jpg\" alt=\"\" width=\"318\" height=\"231\" name=\"graphics15\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Para um carro de massa\u00a0 m<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=1600 kg, calcule o m\u00f3dulo da acelera\u00e7\u00e3o lateral do carro, sabendo que o m\u00f3dulo da for\u00e7a de atrito em cada roda vale F<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>at<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>= 8000 N . Dados:<\/b><\/span><\/span><\/span><span style=\"color: #000000;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #000000;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>sen 3\u00b0 = 0,05 e cos 3\u00b0 = 0,99.<\/b><\/span><\/span><\/span><\/p>\n<p>&nbsp;<\/p>\n<h3><a title=\"Resolu\u00e7\u00e3o comentada dos exerc\u00edcios de vestibulares sobre Conserva\u00e7\u00e3o da Quantidade de Movimento\" href=\"http:\/\/fisicaevestibular.com.br\/novo\/mecanica\/dinamica\/conservacao-da-quantidade-de-movimento\/resolucao-comentada-dos-exercicios-de-vestibulares-sobre-conservacao-da-quantidade-de-movimento\/\"><span style=\"color: #000080;\">Confira a resolu\u00e7\u00e3o comentada<\/span><\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"<p>Exerc\u00edcios de vestibulares com resolu\u00e7\u00e3o comentada sobre Conserva\u00e7\u00e3o da Quantidade de Movimento &nbsp; 01-(PUC-RS)\u00a0Um sistema \u00e9 constitu\u00eddo de duas esferas que se movem sobre um plano horizontal e colidem entre si num determinado instante. Imediatamente ap\u00f3s a colis\u00e3o, pode-se afirmar que, referente ao sistema, permaneceu inalterada a a) energia cin\u00e9tica. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) energia el\u00e1stica. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) quantidade de movimento. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1391,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-1393","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1393","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/comments?post=1393"}],"version-history":[{"count":4,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1393\/revisions"}],"predecessor-version":[{"id":10815,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1393\/revisions\/10815"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1391"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=1393"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}