{"id":3658,"date":"2018-02-13T13:52:02","date_gmt":"2018-02-13T13:52:02","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3658"},"modified":"2024-06-26T15:15:34","modified_gmt":"2024-06-26T15:15:34","slug":"transformacoes-de-energia-energia-mecanica-exercicios-com-caracteristicas-de-enem","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/enem\/transformacoes-de-energia-energia-mecanica-exercicios-com-caracteristicas-de-enem\/","title":{"rendered":"Transforma\u00e7\u00f5es de Energia &#8211; Exerc\u00edcios de ENEM"},"content":{"rendered":"<p align=\"CENTER\"><span style=\"color: #c00000;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>Transforma\u00e7\u00f5es de Energia \u2013 Energia Mec\u00e2nica<\/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>Exerc\u00edcios com caracter\u00edsticas de ENEM<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>01-(UFFRJ-RJ)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_9ccaa99.jpg\" alt=\"\" width=\"774\" height=\"129\" name=\"Imagem 1\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>O salto com vara \u00e9, sem d\u00favida, uma das disciplinas mais exigentes do atletismo. Em um \u00fanico salto, o atleta executa cerca de 23 movimentos em menos de 2 segundos. Na \u00faltima Olimp\u00edada de Atenas a atleta russa, Svetlana Feofanova, bateu o recorde feminino, saltando 4,88 m.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A figura a seguir representa um atleta durante um salto com vara, em tr\u00eas instantes distintos.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_7d7b93bd.jpg\" alt=\"\" width=\"484\" height=\"169\" name=\"Imagem 2\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Assinale a op\u00e7\u00e3o que melhor identifica os tipos de energia envolvidos em cada uma das situa\u00e7\u00f5es I, II, e III, respectivamente.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) &#8211; cin\u00e9tica\u00a0 &#8211; cin\u00e9tica e gravitacional\u00a0 &#8211; cin\u00e9tica e gravitacional<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) &#8211; cin\u00e9tica e el\u00e1stica &#8211; cin\u00e9tica, gravitacional e el\u00e1stica &#8211; cin\u00e9tica e gravitacional<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) &#8211; cin\u00e9tica &#8211; cin\u00e9tica, gravitacional e el\u00e1stica &#8211; cin\u00e9tica e gravitacional<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) &#8211; cin\u00e9tica e el\u00e1stica &#8211; cin\u00e9tica e el\u00e1stica &#8211; gravitacional<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) &#8211; cin\u00e9tica e el\u00e1stica &#8211; cin\u00e9tica e gravitacional \u2013 gravitacional<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>02-(UNICAMP-SP)<\/b><\/span><\/span><\/span><\/p>\n<p><img decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_f3341da7.jpg\" alt=\"\" width=\"774\" height=\"127\" name=\"Imagem 3\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um brinquedo que muito agrada \u00e0s crian\u00e7as s\u00e3o os lan\u00e7adores de objetos em uma pista. Considere que a mola da figura a seguir possui uma constante el\u00e1stica k = 8 000 N\/m e massa desprez\u00edvel. <\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_a04ee475.jpg\" alt=\"\" width=\"660\" height=\"138\" name=\"Imagem 4\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Inicialmente, a mola est\u00e1 comprimida de 2,0 cm e, ao ser<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>liberada, empurra um carrinho de massa igual a 0,20 kg. O carrinho abandona a mola quando esta atinge o seu comprimento relaxado, e percorre uma pista que termina em uma rampa. Considere que n\u00e3o h\u00e1 perda de energia mec\u00e2nica por atrito no movimento do carrinho. A velocidade do carrinho quando ele abandona a mola e a altura da rampa no instante em que o carrinho tem velocidade de 2,0m\/s, valem, respectivamente: (considere g=10N\/kg)<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) 2,0m\/s e 0,3m\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) 6,0m\/s e 0,4m\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) 8,0m\/s e 0,6m\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) 1,2,0m\/s e 1,2m\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) 4,0m\/s e 0,6m<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>03-(FUVEST-SP)<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_68c120f7.jpg\" alt=\"\" width=\"779\" height=\"142\" name=\"Imagem 5\" align=\"BOTTOM\" border=\"0\" \/><span style=\"color: #0000cc;\">\u00a0\u00a0\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>No \u201dsalto com vara\u201d, um atleta corre segurando uma vara e, com per\u00edcia e treino, consegue projetar <\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_651e65aa.jpg\" alt=\"\" width=\"731\" height=\"224\" name=\"Imagem 6\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>seu corpo por cima de uma barra. Para uma estimativa da altura alcan\u00e7ada nesses saltos, \u00e9 poss\u00edvel considerar que a vara sirva apenas para converter o movimento horizontal do atleta (corrida) em movimento vertical, sem perdas ou acr\u00e9scimos de energia. Na an\u00e1lise de um desses saltos, foi obtida a sequ\u00eancia de imagens reproduzida acima.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Nesse caso, \u00e9 poss\u00edvel estimar que a velocidade m\u00e1xima atingida pelo atleta, antes do salto, foi de, aproximadamente,<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Desconsidere os efeitos do trabalho muscular ap\u00f3s o in\u00edcio do salto e considere g=10m\/s<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_6766e361.png\" alt=\"\" width=\"775\" height=\"20\" name=\"Imagem 26\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>04-(UFSM-RS)<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_d2fc0683.jpg\" alt=\"\" width=\"783\" height=\"131\" name=\"Imagem 7\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>N\u00e3o se percebe a exist\u00eancia do ar num dia sem vento; contudo, isso n\u00e3o significa que ele n\u00e3o existe.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um corpo com massa de 2kg \u00e9 abandonado de uma altura de 10m, caindo verticalmente num <\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_b585489e.png\" alt=\"\" width=\"294\" height=\"183\" name=\"Imagem 27\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>referencial fixo no solo. Por efeito da resist\u00eancia do ar, 4J da energia mec\u00e2nica do sistema corpo-Terra se transformam em energia interna do ar e do\u00a0corpo. Considerando o m\u00f3dulo de acelera\u00e7\u00e3o da gravidade como g= 10m\/s<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, o corpo atinge o solo com velocidade de m\u00f3dulo,<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>em m\/s, de<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_6bad55dc.png\" alt=\"\" width=\"774\" height=\"23\" name=\"Imagem 28\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>05-(UNIFESP-SP)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_29c3bb12.jpg\" alt=\"\" width=\"421\" height=\"153\" name=\"Imagem 9\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Um dos brinquedos prediletos de crian\u00e7as no ver\u00e3o \u00e9 o tobo\u00e1gua. A emo\u00e7\u00e3o do brinquedo est\u00e1 associada \u00e0 grande velocidade atingida durante a descida, uma vez que o atrito pode ser desprezado devido \u00e0 presen\u00e7a da \u00e1gua em todo o percurso do brinquedo, bem como \u00e0 exist\u00eancia das curvas fechadas na horizontal, de forma que a crian\u00e7a percorra esses trechos encostada na parede<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_5b736d79.jpg\" alt=\"\" width=\"479\" height=\"213\" name=\"Imagem 10\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>lateral (vertical) do tobo\u00e1gua. <\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Sabendo que a crian\u00e7a de 36 kg parte do repouso, de uma altura de 6,0 m acima da base do tobo\u00e1gua, colocado \u00e0 beira de uma piscina, calcule: Dado: g = 10,0 m\/s<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A for\u00e7a normal, na horizontal, exercida sobre a crian\u00e7a pela parede lateral do tobo\u00e1gua, no ponto <\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_2988c676.jpg\" alt=\"\" width=\"444\" height=\"206\" name=\"Imagem 11\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>indicado na figura (curva do tobo\u00e1gua situada a 2,0 m da sua base) onde o raio de curvatura \u00e9 igual a 80 cm., vale:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) 1.200N\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) 2.400N\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) 3.600N\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) 4.800N\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) 6.000N<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>06-(UFSCAR-SP)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_9ee6e71c.jpg\" alt=\"\" width=\"783\" height=\"134\" name=\"Imagem 12\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma formiga de massa\u00a0m\u00a0encontra-se no topo de uma bola de bilhar rigidamente presa ao solo.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_91d3885d.png\" alt=\"\" width=\"426\" height=\"221\" name=\"Imagem 29\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A bola possui raio\u00a0R\u00a0e superf\u00edcie altamente polida. Considere\u00a0g\u00a0a acelera\u00e7\u00e3o da gravidade e despreze os poss\u00edveis efeitos dissipativos. <\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A formiga come\u00e7a a deslizar na bola com velocidade inicial nula.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>O m\u00f3dulo da velocidade da formiga na altura do solo em que ela perde contato com a bola e o valor dessa altura, s\u00e3o, respectivamente:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) V<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>x<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=\u221a(gh) e h=2R\/3\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) V<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>x<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=\u221a(2gh) e h=R\/3\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) V<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>x<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=\u221a(g\/h) e h=2R\u00a0\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) V<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>x<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=gh e h=R\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) V<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>x<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>=\u221a(g\/2h) e h=2R\/3\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>07-(FGV-RJ)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_84f49b4a.jpg\" alt=\"\" width=\"637\" height=\"133\" name=\"Imagem 14\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>O gr\u00e1fico abaixo representa a energia potencial\u00a0E<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>P<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, em fun\u00e7\u00e3o do tempo, de uma pequena esfera em movimento oscilat\u00f3rio, presa<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_e8c722cc.jpg\" alt=\"\" width=\"777\" height=\"183\" name=\"Imagem 15\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>na extremidade de uma mola. Dentre os gr\u00e1ficos I, II, III e IV, aqueles que representam a energia\u00a0cin\u00e9tica\u00a0e a energia\u00a0total\u00a0do sistema, quando n\u00e3o h\u00e1 efeitos dissipativos, s\u00e3o,\u00a0respectivamente,<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_d4759df3.jpg\" alt=\"\" width=\"777\" height=\"169\" name=\"Imagem 16\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) I e II. \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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) I e III.\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) II e III.\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) II e IV.\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: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>e) III e I.\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>08-(UNESP-SP)<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_bac37db2.jpg\" alt=\"\" width=\"780\" height=\"166\" name=\"Imagem 17\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>O Skycoaster \u00e9 uma atra\u00e7\u00e3o existente em grandes parques de divers\u00e3o, representado nas figuras a seguir. Considere que em um desses brinquedos, tr\u00eas aventureiros s\u00e3o presos a cabos de a\u00e7o e i\u00e7ados a grande altura. Os jovens, que\u00a0se\u00a0\u00a0 movem juntos no<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_e499384a.jpg\" alt=\"\" width=\"780\" height=\"159\" name=\"Imagem 18\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>brinquedo, t\u00eam massas iguais a 50 kg cada um. Depois de solto um dos cabos, passam a oscilar tal como um p\u00eandulo simples, atingindo uma altura m\u00e1xima de 60 metros e chegando a uma altura m\u00ednima do ch\u00e3o de apenas 2 metros. Nessas\u00a0condi\u00e7\u00f5es e desprezando a a\u00e7\u00e3o de for\u00e7as de resist\u00eancias, o valor da maior energia cin\u00e9tica, em kJ, a que eles ficam submetidos, \u00e9, aproximadamente de:<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_e1508d3f.png\" alt=\"\" width=\"775\" height=\"21\" name=\"Imagem 30\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>09-(UERJ-RJ)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_ba00049d.jpg\" alt=\"\" width=\"780\" height=\"140\" name=\"Imagem 19\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Os esquemas a seguir mostram quatro rampas AB, de mesma altura AC e perfis distintos, fixadas em mesas id\u00eanticas, nas quais uma pequena pedra \u00e9 abandonada, do ponto A, a partir do 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\/enem\/13\/ENEM13_html_858b8e24.jpg\" alt=\"\" width=\"780\" height=\"151\" name=\"Imagem 20\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Ap\u00f3s deslizar sem atrito pelas rampas I, II, III e IV, a pedra toca o solo, pela primeira vez, a uma dist\u00e2ncia do ponto B respectivamente igual a d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>, dII, d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>III<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0e d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>IV<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>A rela\u00e7\u00e3o entre essas dist\u00e2ncias est\u00e1 indicada na seguinte alternativa:<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0&gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>II<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0= d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>III<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0&gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>IV<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>b) d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>II<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I &gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>II<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0&gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>IV<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0&gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>c) d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>II<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0&gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>IV<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0= d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0&gt; d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>III<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>d) d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>I<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0= d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>II<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0= d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>III<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0= d<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sub><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>IV<\/b><\/span><\/span><\/sub><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>10-(UFF-RJ)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_42b30114.jpg\" alt=\"\" width=\"776\" height=\"159\" name=\"Imagem 21\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Dois brinquedos id\u00eanticos, que lan\u00e7am dardos usando molas, s\u00e3o disparados simultaneamente na vertical para baixo.<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_d008bb72.jpg\" alt=\"\" width=\"545\" height=\"193\" name=\"Imagem 22\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>As molas com os respectivos dardos foram inicialmente comprimidas at\u00e9 a posi\u00e7\u00e3o 1 e, ent\u00e3o, liberadas. A \u00fanica diferen\u00e7a entre os dardos I e II, conforme mostra a figura, \u00e9 que I tem um peda\u00e7o de chumbo grudado nele, o que n\u00e3o existe em II.<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Escolha o gr\u00e1fico que representa as velocidades dos dardos I e II, como fun\u00e7\u00e3o do tempo, a partir do instante em que eles saem dos canos dos brinquedos.<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_e423e6c5.jpg\" alt=\"\" width=\"776\" height=\"167\" name=\"Imagem 23\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial\\ Black, serif;\"><span style=\"font-size: large;\"><b>11-(PUC-SP)\u00a0<\/b><\/span><\/span><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_13f8e056.jpg\" alt=\"\" width=\"776\" height=\"159\" name=\"Imagem 24\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Uma crian\u00e7a de massa 25 kg, inicialmente no ponto A, distante 2,4 m do solo, percorre, a partir do repouso, o escorregador esquematizado na figura. O escorregador pode ser considerado um plano inclinado cujo \u00e2ngulo com a horizontal \u00e9 de 37\u00b0. Supondo o coeficiente de atrito cin\u00e9tico entre a roupa da crian\u00e7a e o escorregador igual a 0,5, a velocidade com que a crian\u00e7a chega \u00e0 base do escorregador (ponto B) \u00e9, em m\/s, (g=10m\/s<\/b><\/span><\/span><\/span><span style=\"color: #0000cc;\"><sup><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>2<\/b><\/span><\/span><\/sup><\/span><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>)<\/b><\/span><\/span><\/span><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone\" src=\"http:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/enem\/13\/ENEM13_html_52b50e93.jpg\" alt=\"Energia\" width=\"570\" height=\"207\" name=\"Imagem 25\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>Dados: sen 37\u00b0 = 0,6; cos 37\u00b0 = 0,8; tg 37\u00b0 = 0,75<\/b><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #0000cc;\"><span style=\"font-family: Arial, serif;\"><span style=\"font-size: medium;\"><b>a) 4\u221a3\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0b) 4\u221a5\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c) 16\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0d) 4\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e) 6\u221a3<\/b><\/span><\/span><\/span><\/p>\n<p>&nbsp;<\/p>\n<h3><a title=\"Resolu\u00e7\u00e3o Comentada \u2013 Transforma\u00e7\u00f5es de Energia \u2013 Energia Mec\u00e2nica\" href=\"http:\/\/fisicaevestibular.com.br\/novo\/enem\/transformacoes-de-energia-energia-mecanica-exercicios-com-caracteristicas-de-enem\/resolucao-comentada-transformacoes-de-energia-energia-mecanica\/\"><span style=\"color: #000080;\">Confira a resolu\u00e7\u00e3o comentada<\/span><\/a><\/h3>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/fisicaevestibular.com.br\/novo\/enem\/\">Clique aqui para ver sobre o tema!<\/a><\/p>\n<p><a href=\"https:\/\/www.youtube.com\/user\/fisicaevestibular\/playlists\">Confira as v\u00eddeo aulas!<\/a><span style=\"color: #0000cc;\">\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Transforma\u00e7\u00f5es de Energia \u2013 Energia Mec\u00e2nica Exerc\u00edcios com caracter\u00edsticas de ENEM \u00a0 01-(UFFRJ-RJ)\u00a0 O salto com vara \u00e9, sem d\u00favida, uma das disciplinas mais exigentes do atletismo. Em um \u00fanico salto, o atleta executa cerca de 23 movimentos em menos de 2 segundos. Na \u00faltima Olimp\u00edada de Atenas a atleta russa, Svetlana Feofanova, bateu o recorde feminino, saltando 4,88 m.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3575,"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-3658","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3658","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=3658"}],"version-history":[{"count":5,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3658\/revisions"}],"predecessor-version":[{"id":9789,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3658\/revisions\/9789"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3575"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}