{"id":3517,"date":"2018-01-19T02:49:13","date_gmt":"2018-01-19T02:49:13","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3517"},"modified":"2024-09-04T12:39:12","modified_gmt":"2024-09-04T12:39:12","slug":"resolucao-comentada-das-questoes-de-fisica","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2018\/santa-casa\/resolucao-comentada-das-questoes-de-fisica\/","title":{"rendered":"Resolu\u00e7\u00e3o comentada das quest\u00f5es de F\u00cdSICA"},"content":{"rendered":"

Resolu\u00e7\u00e3o comentada das quest\u00f5es de F\u00cdSICA da<\/span><\/span><\/span><\/p>\n

(Faculdade de Ci\u00eancias M\u00e9dicas da Santa Casa de S\u00e3o Paulo – <\/b><\/span><\/span><\/span><\/p>\n

\u2013 2018)<\/b><\/span><\/span><\/span><\/p>\n

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

Veja abaixo,<\/b><\/span><\/span><\/span> <\/b>a <\/b><\/span><\/span><\/span>figura ilustrativa da situa\u00e7\u00e3o apresentada:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

02- <\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

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

Segunda lei de Kepler (lei das \u00e1reas)<\/b><\/span><\/span><\/span><\/p>\n

\u201c\u00a0O\u00a0<\/b><\/span><\/span><\/span>segmento de reta imagin\u00e1rio<\/b><\/span><\/span><\/span>\u00a0que une o\u00a0<\/b><\/span><\/span><\/span>centro do Sol ao centro do planeta varre \u00e1reas iguais em per\u00edodos de tempo iguais\u201d\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

A figura abaixo representa um\u00a0<\/b><\/span><\/span><\/span>planeta em \u00f3rbita el\u00edptica ao redor do Sol.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

04- <\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Pelo princ\u00edpio da conserva\u00e7\u00e3o da quantidade de movimento, em todo tipo de choques, <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>quantidade de movimento do sistema antes do choque Q<\/b><\/span><\/span><\/span>sa<\/b><\/span><\/span><\/sub><\/span> <\/b>\u00e9 igual \u00e0 quantidade de movimento do sistema depois do choque Q<\/b><\/span><\/span><\/span>sd<\/b><\/span><\/span><\/sub><\/span>. <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

05- <\/span><\/span><\/span>O <\/b><\/span><\/span><\/span>enunciado<\/b><\/span><\/span><\/span> pede a <\/b><\/span><\/span><\/span>energia mec\u00e2nica dissipada <\/b><\/span><\/span><\/span>desde o <\/b><\/span><\/span><\/span>in\u00edcio das oscila\u00e7\u00f5es <\/b><\/span><\/span><\/span>(<\/b><\/span><\/span><\/span>ponto A, <\/b><\/span><\/span><\/span>parte do repouso, V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> = 0 e a <\/b><\/span><\/span><\/span>energia cin\u00e9tica em A <\/b><\/span><\/span><\/span>\u201cE<\/b><\/span><\/span><\/span>cA<\/b><\/span><\/span><\/sub><\/span> = mV<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/2\u201d <\/b><\/span><\/span><\/span>\u00e9 nula<\/b><\/span><\/span><\/span>) at\u00e9 o <\/b><\/span><\/span><\/span>final das oscila\u00e7\u00f5es <\/b><\/span><\/span><\/span>(<\/b><\/span><\/span><\/span>ponto B<\/b><\/span><\/span><\/span>, para instantaneamente, V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = 0 e a <\/b><\/span><\/span><\/span>energia cin\u00e9tica em B<\/b><\/span><\/span><\/span> \u201cE<\/b><\/span><\/span><\/span>cB<\/b><\/span><\/span><\/sub><\/span> = mV<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/2\u201d <\/b><\/span><\/span><\/span>\u00e9 nula<\/b><\/span><\/span><\/span>).<\/b><\/span><\/span><\/span><\/p>\n

Assim, a <\/b><\/span><\/span><\/span>energia mec\u00e2nica dissipada (\u2206E<\/b><\/span><\/span><\/span>md<\/b><\/span><\/span><\/sub><\/span>) corresponde apenas \u00e0 varia\u00e7\u00e3o da energia potencial gravitacional (E<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span> = m.g.h).<\/b><\/span><\/span><\/span><\/p>\n

Considerando apenas os <\/b><\/span><\/span><\/span>pontos pedidos (A e B) <\/b><\/span><\/span><\/span>e colocando o <\/b><\/span><\/span><\/span>referencial (n\u00edvel zero de altura) <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>B, <\/b><\/span><\/span><\/span>voc\u00ea ter\u00e1 que a <\/b><\/span><\/span><\/span>energia potencial gravitacional em B \u00e9 nula, (E<\/b><\/span><\/span><\/span>pB<\/b><\/span><\/span><\/sub><\/span> <\/b>= m.g.h<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = m.g.0 <\/b><\/span><\/span><\/span>= 0) \"\"<\/b><\/span><\/span><\/span> <\/b>E<\/b><\/span><\/span><\/span>pB<\/b><\/span><\/span><\/sub><\/span> = 0.<\/b><\/span><\/span><\/span><\/p>\n

Para <\/b><\/span><\/span><\/span>calcular<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>energia potencial gravitacional em A <\/b><\/span><\/span><\/span>(E<\/b><\/span><\/span><\/span>PA<\/b><\/span><\/span><\/sub><\/span> = m.g.h<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>), a <\/b><\/span><\/span><\/span>altura h<\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/sub><\/span>\u00e9 determinada conforme a <\/b><\/span><\/span><\/span>figura abaixo:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

06- <\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

Veja as express\u00f5es abaixo que se referem \u00e0 refra\u00e7\u00e3o da luz:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Lei de Snell-Descartes<\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

\"\"<\/p>\n

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

\"\"<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

Se voc\u00ea n\u00e3o domina a teoria pode encontra-la em fisicaevestibular.com.br \u2013 Eletricidade \u2013 Eletromagnetismo -for\u00e7a eletromotriz induzida.<\/b><\/span><\/span><\/span><\/p>\n

\"\" Com <\/b><\/span><\/span><\/span>x variando entre 0 e L (x < 0 < L),<\/b><\/span><\/span><\/span> espira <\/b><\/span><\/span><\/span>entrando na regi\u00e3o do campo <\/b><\/span><\/span><\/span>at\u00e9 ficar totalmente imersa, ent\u00e3o a varia\u00e7\u00e3o de <\/b><\/span><\/span><\/span>fluxo magn\u00e9tico no interior da espira est\u00e1 aumentando.<\/b><\/span><\/span><\/span><\/p>\n

Nesse caso,\u00a0<\/b><\/span><\/span><\/span>pela lei de Lenz,\u00a0<\/b><\/span><\/span><\/span>deve surgir um\u00a0<\/b><\/span><\/span><\/span>fluxo magn\u00e9tico\u00a0<\/b><\/span><\/span><\/span>que\u00a0<\/b><\/span><\/span><\/span>se oponha a esse aumento de fluxo, <\/b><\/span><\/span><\/span>ou seja,\u00a0<\/b><\/span><\/span><\/span>deve surgir um fluxo magn\u00e9tico que esteja\u00a0saindo\u00a0da folha.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Com\"\"\u00a0<\/b><\/span><\/span><\/span>saindo da folha,\u00a0<\/b><\/span><\/span><\/span>usando a\u00a0<\/b><\/span><\/span><\/span>regra da m\u00e3o direita, o sentido da corrente el\u00e9trica induzida est\u00e1 indicado nas figuras acima (sentido anti hor\u00e1rio).<\/b><\/span><\/span><\/span><\/p>\n

\"\" Enquanto a <\/b><\/span><\/span><\/span>espira estiver totalmente imersa<\/b><\/span><\/span><\/span> no interior da regi\u00e3o do <\/b><\/span><\/span><\/span>campo magn\u00e9tico (x < L< 3L)<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a <\/b><\/span><\/span><\/span>corrente el\u00e9trica induzida \u00e9 nula<\/b><\/span><\/span><\/span> (n\u00e3o ocorre varia\u00e7\u00e3o de fluxo magn\u00e9tico no interior da espira).<\/b><\/span><\/span><\/span><\/p>\n

\"\" Com <\/b><\/span><\/span><\/span>x variando entre 0 e L (3L < x < 4L),<\/b><\/span><\/span><\/span> espira <\/b><\/span><\/span><\/span>saindo regi\u00e3o do campo <\/b><\/span><\/span><\/span>at\u00e9 ficar totalmente fora dessa regi\u00e3o, ent\u00e3o a varia\u00e7\u00e3o de <\/b><\/span><\/span><\/span>fluxo magn\u00e9tico no interior da espira est\u00e1 diminuindo.<\/b><\/span><\/span><\/span><\/p>\n

Nesse caso, pela\u00a0<\/b><\/span><\/span><\/span>lei de Lenz,\u00a0<\/b><\/span><\/span><\/span>deve surgir um\u00a0<\/b><\/span><\/span><\/span>fluxo magn\u00e9tico que se oponha a essa diminui\u00e7\u00e3o\u00a0<\/b><\/span><\/span><\/span>de\u00a0<\/b><\/span><\/span><\/span>fluxo<\/b><\/span><\/span><\/span>, ou seja, deve\u00a0<\/b><\/span><\/span><\/span>surgir um fluxo magn\u00e9tico que esteja\u00a0entrando\u00a0na folha.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Com\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>entrando da folha<\/b><\/span><\/span><\/span>, usando a\u00a0<\/b><\/span><\/span><\/span>regra da m\u00e3o direita, o sentido da corrente el\u00e9trica induzida est\u00e1 indicado nas figuras acima (sentido hor\u00e1rio).<\/b><\/span><\/span><\/span><\/p>\n

R- C\u00a0<\/b><\/span><\/span><\/span><\/p>\n

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

Resolu\u00e7\u00e3o comentada das quest\u00f5es de F\u00cdSICA da (Faculdade de Ci\u00eancias M\u00e9dicas da Santa Casa de S\u00e3o Paulo – \u2013 2018) 01- Veja abaixo, a figura ilustrativa da situa\u00e7\u00e3o apresentada: 02- R- E 03- Segunda lei de Kepler (lei das \u00e1reas) \u201c\u00a0O\u00a0segmento de reta imagin\u00e1rio\u00a0que une o\u00a0centro do Sol ao centro do planeta varre \u00e1reas iguais em per\u00edodos de tempo iguais\u201d\u00a0\u00a0<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3515,"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-3517","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3517","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=3517"}],"version-history":[{"count":3,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3517\/revisions"}],"predecessor-version":[{"id":11064,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3517\/revisions\/11064"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3515"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}