{"id":2713,"date":"2017-02-07T03:37:48","date_gmt":"2017-02-07T03:37:48","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=2713"},"modified":"2024-09-03T17:33:50","modified_gmt":"2024-09-03T17:33:50","slug":"resolucao-comentada-dos-exercicios-da-unicamp-sp-2017","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2017\/unicamp-2017\/resolucao-comentada-dos-exercicios-da-unicamp-sp-2017\/","title":{"rendered":"Resolu\u00e7\u00e3o comentada dos exerc\u00edcios da UNICAMP-SP-2017"},"content":{"rendered":"

Resolu\u00e7\u00e3o comentada dos exerc\u00edcios da <\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

UNICAMP-SP-2017<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

01- <\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Enunciado do princ\u00edpio de Arquimedes<\/b><\/span><\/span><\/span><\/span><\/p>\n

\u201cTodo corpo total ou parcialmente mergulhado num l\u00edquido em equil\u00edbrio,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>recebe uma<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>for\u00e7a <\/b><\/span><\/span>de <\/b><\/span><\/span>dire\u00e7\u00e3o vertical e sentido\u00a0 para cima<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>denominada de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>Empuxo,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>cuja <\/b><\/span><\/span>intensidade\u00a0 \u00e9 igual ao peso do volume de l\u00edquido deslocado\u201c<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Quando o texto afirma<\/b><\/span><\/span>: <\/b><\/span> (…) a <\/b><\/span><\/span>gravidade espec\u00edfica do corpo humano<\/b><\/span><\/span>, em sua <\/b><\/span><\/span>condi\u00e7\u00e3o natural, \u00e9 quase igual \u00e0 massa de \u00e1gua doce que ele desloca.<\/b><\/span><\/span> (…), essa <\/b><\/span><\/span>gravidade espec\u00edfica<\/b><\/span><\/span> est\u00e1 se referindo ao termo <\/b><\/span><\/span>densidade<\/b><\/span><\/span> j\u00e1 que a <\/b><\/span><\/span>densidade do corpo humano \u00e9 quase igual \u00e0 densidade da \u00e1gua.<\/b><\/span><\/span><\/span><\/span><\/p>\n

J\u00e1 quando o texto afirma que as <\/b><\/span><\/span>gravidades do corpo e da massa de \u00e1gua deslocada<\/b><\/span><\/span> s\u00e3o muito<\/b><\/span><\/span> <\/b>delicadamente equilibradas,<\/b><\/span><\/span> e que uma <\/b><\/span><\/span>ninharia<\/b><\/span><\/span> pode fazer com que <\/b><\/span><\/span>uma delas predomine, ele est\u00e1 se referindo ao peso do corpo (vertical e para baixo, constante) e ao empuxo (vertical e para cima que depende do volume de \u00e1gua deslocada).<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

R- A<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

02- <\/b><\/span><\/span><\/span>Pelo enunciado o <\/b><\/span><\/span>aproveitamento<\/b><\/span><\/span> da energia e\u00f3lica ocorre por <\/b><\/span><\/span>meio da convers\u00e3o da <\/b><\/span><\/span>energia cin\u00e9tica <\/b><\/span><\/span>(E<\/b><\/span><\/span>c<\/b><\/span><\/sub><\/span>) de transla\u00e7\u00e3o em <\/b><\/span><\/span>energia cin\u00e9tica<\/b><\/span><\/span> de<\/b><\/span><\/span> <\/b>rota\u00e7\u00e3o.<\/b><\/span><\/span><\/p>\n

A <\/b><\/span><\/span>an\u00e1lise das turbinas e\u00f3licas<\/b><\/span><\/span> \u00e9 <\/b><\/span><\/span>complexa porque envolve aerodin\u00e2mica e mec\u00e2nica dos fluidos.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Contudo, os <\/b><\/span><\/span>conceitos b\u00e1sicos podem ser obtidos a partir de simplifica\u00e7\u00f5es na an\u00e1lise.<\/b><\/span><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span>energia contida no vento horizontal \u00e9 basicamente sua <\/b><\/span><\/span>energia cin\u00e9tica,<\/b><\/span><\/span> uma vez que <\/b><\/span><\/span>n\u00e3o h\u00e1<\/b><\/span><\/span> <\/b>varia\u00e7\u00e3o de press\u00e3o, varia\u00e7\u00e3o de altitude,<\/b><\/span><\/span> e, pelo enunciado, a <\/b><\/span><\/span>densidade do ar permanece<\/b><\/span><\/span> <\/b>constante<\/b><\/span><\/span> o que implica que a <\/b><\/span><\/span>massa de ar <\/b><\/span><\/span>m<\/b><\/span><\/span> que atravessa os permanece constante<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

A<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>energia cin\u00e9tica<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00e9 uma<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>grandeza escalar,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>n\u00e3o tem dire\u00e7\u00e3o nem sentido, <\/b><\/span><\/span>apenas intensidade, fornecida pela express\u00e3o:<\/b><\/span><\/span>.<\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

R- B<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

03- <\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

R- A<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

\"Captura<\/a><\/p>\n

\"\"<\/p>\n

\"Captura<\/a><\/p>\n

05- \"\"<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

for\u00e7as deve ser fechado).<\/b><\/span><\/span><\/span><\/span><\/p>\n

Observa\u00e7\u00e3o: <\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

R- C<\/b><\/span><\/span><\/span><\/span><\/p>\n

Observa\u00e7\u00e3o: <\/b><\/span><\/span>Para <\/b><\/span><\/span>resolver esse exerc\u00edcio<\/b><\/span><\/span> voc\u00ea deve <\/b><\/span><\/span>supor que a for\u00e7a trocada entre as costas da pessoa e o espaldar do assento seja nula.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

06- <\/b><\/span><\/span><\/span>Do total <\/b><\/span><\/span>da <\/b><\/span><\/span>energia cin\u00e9tica <\/b><\/span><\/span>relacionada com o movimento de rota\u00e7\u00e3o<\/b><\/span><\/span> do Pulsar equivalente a 2.10<\/b><\/span><\/span>42<\/b><\/span><\/sup><\/span> J, <\/b><\/span><\/span>ap\u00f3s um ano foi perdido<\/b><\/span><\/span> 0,1% desse valor sob forma de <\/b><\/span><\/span>radia\u00e7\u00e3o eletromagn\u00e9tica.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Assim,<\/b><\/span><\/span> a <\/b><\/span><\/span>energia cin\u00e9tica irradiada <\/b><\/span><\/span>pelo Pulsar foi de E<\/b><\/span><\/span>c<\/b><\/span><\/sub><\/span> <\/b>= \"\" 2.10<\/b><\/span><\/span>42<\/b><\/span><\/sup><\/span> \"\" <\/b><\/span><\/span>E<\/b><\/span><\/span>c<\/b><\/span><\/sub><\/span> = 2,0.10<\/b><\/span><\/span>39<\/b><\/span><\/sup><\/span> J.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Como Pot\u00eancia = \"\" \"\" a pot\u00eancia irradiada pelo Pulsar ap\u00f3s 1 ano (3,6.10<\/b><\/span><\/span>7<\/b><\/span><\/sup><\/span> s) ser\u00e1 \"\" P = <\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\" =<\/b><\/span><\/span> <\/b>0,56.10<\/b><\/span><\/span>32<\/b><\/span><\/sup><\/span> <\/b> \"\" <\/b><\/span><\/span><\/span>P = 5,6.10<\/b><\/span><\/span>31<\/b><\/span><\/sup><\/span> J<\/b><\/span><\/span><\/span><\/span><\/p>\n

R- C<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

07- \"\"<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

R- A<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

08- <\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Equa\u00e7\u00e3o da continuidade<\/b><\/span><\/span><\/span><\/span><\/p>\n

Considere<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>tr\u00eas peda\u00e7os de tubos com di\u00e2metros diversos e \u00e1reas de se\u00e7\u00e3o transversal S<\/b><\/span><\/span>1<\/b><\/span><\/sub><\/span>,<\/b><\/span><\/span> <\/b>S<\/b><\/span><\/span>2<\/b><\/span><\/sub><\/span>\u00a0e<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>S<\/b><\/span><\/span>3<\/b><\/span><\/sub><\/span>\u00a0conectados, <\/b><\/span><\/span>e com <\/b><\/span><\/span>\u00e1gua escoando atrav\u00e9s deles no sentido de A para B, com velocidades de intensidades V<\/b><\/span><\/span>1<\/b><\/span><\/sub><\/span>, V<\/b><\/span><\/span>2<\/b><\/span><\/sub><\/span>\u00a0e V<\/b><\/span><\/span>3<\/b><\/span><\/sub><\/span>, respectivamente.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Essa equa\u00e7\u00e3o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>Z = S.v,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>denominada<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>equa\u00e7\u00e3o da continuidade<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>afirma que a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>velocidade<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>com que o l\u00edquido escoa no interior do tubo \u00e9<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>inversamente proporcional \u00e0 \u00e1rea de se\u00e7\u00e3o transversal (S)<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>do mesmo, ou seja,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>diminuindo a \u00e1rea, a velocidade (v) com que o l\u00edquido flui aumenta na mesma<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>propor\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

No caso do <\/b><\/span><\/span>exerc\u00edcio,<\/b><\/span><\/span> supondo que a <\/b><\/span><\/span>massa de l\u00edquido que deixa a seringa seja igual \u00e0 massa de<\/b><\/span><\/span> <\/b>l\u00edquido que penetra no microcana<\/b><\/span><\/span>l e supondo tamb\u00e9m que o <\/b><\/span><\/span>l\u00edquido incompress\u00edvel (densidade constante), o volume transferido (\u2206V<\/b><\/span><\/span>seringa<\/b><\/span><\/sub><\/span>) da seringa para o microcanal ((\u2206V<\/b><\/span><\/span>microcanal)<\/b><\/span><\/sub><\/span> por unidade de<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

 <\/p>\n

09- <\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

 <\/p>\n

10- \"\"<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Nesse <\/b><\/span><\/span>microsc\u00f3pio de luz,<\/b><\/span><\/span> a <\/b><\/span><\/span>velocidade<\/b><\/span><\/span> de propaga\u00e7\u00e3o <\/b><\/span><\/span>da luz<\/b><\/span><\/span> \u00e9 <\/b><\/span><\/span>constante e vale V = c = 3.10<\/b><\/span><\/span>8<\/b><\/span><\/sup><\/span> m\/s,<\/b><\/span><\/span> e assim, pela <\/b><\/span><\/span>equa\u00e7\u00e3o fundamental da ondulat\u00f3ria V = constante =c = \u03bb.f,<\/b><\/span><\/span> o <\/b><\/span><\/span>comprimento de onda \u03bb \u00e9 inversamente proporciona \u00e0 frequ\u00eancia f.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Como pelo enunciado, o intervalo <\/b><\/span><\/span>de frequ\u00eancias do espectro de luz vis\u00edvel<\/b><\/span><\/span> est\u00e1 <\/b><\/span><\/span>compreendido <\/b><\/span><\/span>entre 4<\/b><\/span><\/span>,0.10<\/b><\/span><\/span>14<\/b><\/span><\/sup><\/span> Hz e 7,5.10<\/b><\/span><\/span>14<\/b><\/span><\/sup><\/span> Hz<\/b><\/span><\/span>, a <\/b><\/span><\/span>menor estrutura celular<\/b><\/span><\/span> (menor \u03bb) que se <\/b><\/span><\/span>poderia observar<\/b><\/span><\/span> nesse <\/b><\/span><\/span>microsc\u00f3pio de luz<\/b><\/span><\/span> corresponde \u00e0 <\/b><\/span><\/span>maior frequ\u00eacia nesse intervalo que \u00e9 de \u00e9 de f = 7,5.10<\/b><\/span><\/span>14<\/b><\/span><\/sup><\/span> Hz.<\/b><\/span><\/span><\/span><\/span><\/p>\n

c = \u03bb.f<\/b><\/span><\/span> \"\" 3.10<\/b><\/span><\/span>8<\/b><\/span><\/sup><\/span> = \u03bb.7,5.10<\/b><\/span><\/span>14<\/b><\/span><\/sup><\/span> \"\" \u03bb = \"\"<\/b><\/span><\/span> \"\" <\/b><\/span><\/span><\/span>\u03bb = 0,4.10<\/b><\/span><\/span>-6<\/b><\/span><\/sup><\/span> \"\" <\/b><\/span><\/span>\u03bb = 4.10<\/b><\/span><\/span>-7<\/b><\/span><\/sup><\/span> m = 400 nm.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Portanto, <\/b><\/span><\/span>observando a figura<\/b><\/span><\/span> voc\u00ea percebe que a <\/b><\/span><\/span>menor estrutura celular que voc\u00ea pode perceber<\/b><\/span><\/span> nesse <\/b><\/span><\/span>microsc\u00f3pio<\/b><\/span><\/span> \u00e9 o <\/b><\/span><\/span>Ret\u00edculo Endoplasm\u00e1tico dimens\u00e3o 420 nm.<\/b><\/span><\/span><\/span><\/span><\/p>\n

R- B<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

11- <\/b><\/span><\/span><\/span>O <\/b><\/span><\/span>comportamento do bal\u00e3o de Natal<\/b><\/span><\/span> como espelho <\/b><\/span><\/span>\u00e9 id\u00eantico ao fornecido por um espelho esf\u00e9rico<\/b><\/span><\/span> <\/b>convexo,<\/b><\/span><\/span> com as <\/b><\/span><\/span>seguintes caracter\u00edsticas<\/b><\/span><\/span>:<\/span><\/span><\/span><\/p>\n

Constru\u00e7\u00e3o geom\u00e9trica de imagens nos espelhos esf\u00e9ricos convexos<\/b><\/span><\/span><\/span><\/span><\/p>\n

Espelho convexo<\/b><\/span><\/span>\u00a0\"\"\u00a0<\/b><\/span><\/span>Para <\/b><\/span><\/span>qualquer localiza\u00e7\u00e3o do objeto Independentemente <\/b><\/span><\/span>de sua posi\u00e7\u00e3o, a<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

imagem ter\u00e1 sempre:<\/b><\/span><\/span><\/span><\/span><\/p>\n

Natureza<\/b><\/span><\/span>\u00a0\"\"<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>virtual<\/b><\/span><\/span><\/span><\/span><\/p>\n

Localiza\u00e7\u00e3o<\/b><\/span><\/span>\u00a0\"\"\u00a0<\/b><\/span><\/span>atr\u00e1s do espelho e entre V e F<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>e observe nas<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>figuras acima<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>que<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>\u00e0 <\/b><\/span><\/span>medida que o objeto se aproxima do espelho, a imagem tamb\u00e9m se aproxima e aumenta de tamanho, mas est\u00e1 sempre entre V e F.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Tamanho<\/b><\/span><\/span>\u00a0\"\"\u00a0<\/b><\/span><\/span>menor que o do objeto<\/b><\/span><\/span><\/span><\/span><\/p>\n

Orienta\u00e7\u00e3o<\/b><\/span><\/span>\u00a0\"\"<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>direita em rela\u00e7\u00e3o ao objeto<\/b><\/span><\/span><\/span><\/span><\/p>\n

Utilidades:<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>Os<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>espelhos convexos<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>s\u00e3o empregados como<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>retrovisores em ve\u00edculos, cabines de seguran\u00e7a, elevadores, etc.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Sua <\/b><\/span><\/span>vantagem <\/b><\/span><\/span>sobre o espelho plano, nesse particular, \u00e9 ter<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>maior campo visual.<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>T\u00eam, entretanto, o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>inconveniente<\/b><\/span><\/span> de n\u00e3o darem no\u00e7\u00e3o da dist\u00e2ncia.<\/b><\/span><\/span><\/span><\/span><\/p>\n

R- B<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

Voltar para os exerc\u00edcios<\/span><\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"

Resolu\u00e7\u00e3o comentada dos exerc\u00edcios da UNICAMP-SP-2017 01- Enunciado do princ\u00edpio de Arquimedes \u201cTodo corpo total ou parcialmente mergulhado num l\u00edquido em equil\u00edbrio,\u00a0recebe uma\u00a0for\u00e7a de dire\u00e7\u00e3o vertical e sentido\u00a0 para cima\u00a0denominada de\u00a0Empuxo,\u00a0cuja intensidade\u00a0 \u00e9 igual ao peso do volume de l\u00edquido deslocado\u201c Quando o texto afirma: (…) a gravidade espec\u00edfica do corpo humano, em sua condi\u00e7\u00e3o natural, \u00e9 quase igual \u00e0<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2711,"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-2713","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2713","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=2713"}],"version-history":[{"count":3,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2713\/revisions"}],"predecessor-version":[{"id":3240,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2713\/revisions\/3240"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2711"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=2713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}