{"id":694,"date":"2015-05-12T18:18:21","date_gmt":"2015-05-12T18:18:21","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=694"},"modified":"2024-09-03T12:46:12","modified_gmt":"2024-09-03T12:46:12","slug":"resolucao-comentada-da-ufsc-2015","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2015\/exercicios-resolvidos-da-ufsc-2015\/resolucao-comentada-da-ufsc-2015\/","title":{"rendered":"Resolu\u00e7\u00e3o Comentada da UFSC 2015"},"content":{"rendered":"

RESOLU\u00c7\u00d5ES<\/b><\/span><\/span><\/span><\/p>\n

01- <\/b><\/span><\/span><\/span>01. <\/b><\/span><\/span><\/span>nas <\/b><\/span><\/span><\/span>l\u00e2mpadas incandescentes<\/b><\/span><\/span><\/span> ocorre o <\/b><\/span><\/span><\/span>efeito Joule<\/b><\/span><\/span><\/span>, que provoca o <\/b><\/span><\/span><\/span>aquecimento do filamento de tungst\u00eanio (resistor). <\/b><\/span><\/span><\/span><\/p>\n

01. Correta \"\" <\/b><\/span><\/span><\/span>As l\u00e2mpadas incandescentes utilizam um fio de <\/b><\/span><\/span><\/span>tungst\u00eanio<\/b><\/span><\/span><\/span> encerrado num bulbo de<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

vidro. Esse fio tem di\u00e2metro inferior a 0,1 mm e \u00e9 enrolado segundo uma h\u00e9lice cil\u00edndrica. Passando <\/b><\/span><\/span><\/span>corrente el\u00e9trica no filamento, ele se aquece a uma temperatura da ordem de 3.000 \u00ba C<\/b><\/span><\/span><\/span>. O filamento torna-se, ent\u00e3o, <\/b><\/span><\/span><\/span>incandescente (por efeito Joule) e come\u00e7a a emitir luz.<\/b><\/span><\/span><\/span> No interior da l\u00e2mpada n\u00e3o pode haver ar, pois dos contr\u00e1rio o filamento se oxida e incendeia-se<\/b><\/span><\/span><\/span>.<\/span><\/span>\u00a0<\/span><\/span><\/p>\n

02. <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>controle remo<\/b><\/span><\/span><\/span>to opera com a emiss\u00e3o de <\/b><\/span><\/span><\/span>ondas mec\u00e2nicas transversais<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

02. Falsa \"\" <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>controle remo<\/b><\/span><\/span><\/span>to opera com a emiss\u00e3o de <\/b><\/span><\/span><\/span>ondas eletromagn\u00e9ticas transversais<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>como <\/b><\/span><\/span><\/span>transfere calor de uma fonte fria para uma fonte quente<\/b><\/span><\/span><\/span>, o aparelho de ar condicionado <\/b><\/span><\/span><\/span>viola a Segunda Lei da Termodin\u00e2mica<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

04. Falsa \"\" <\/b><\/span><\/span><\/span>o calor n\u00e3o pode fluir, de forma espont\u00e2nea, de um corpo de temperatura menor, para um outro corpo de temperatura ,mais alta.Tendo como consequ\u00eancia que o sentido natural do fluxo de calor \u00e9 <\/b><\/span><\/span><\/span>da temperatura mais alta para a mais baixa, e que para que o fluxo seja universo necess\u00e1rio que um agente externo realize um trabalho sobre este sistema (o que n\u00e3o viola a segunda lei da Termodin\u00e2mica).<\/b><\/span><\/span><\/span><\/p>\n

08. <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>velocidade de transla\u00e7\u00e3o <\/b><\/span><\/span><\/span>de uma bicicleta pode ser alterada pela <\/b><\/span><\/span><\/span>modifica\u00e7\u00e3o da raz\u00e3o Raio da coroa pelo Raio da catraca, <\/b><\/span><\/span><\/span>que est\u00e3o ligadas aos pedais e \u00e0 roda. <\/b><\/span><\/span><\/span><\/p>\n

08. Correta \"\" <\/b><\/span><\/span><\/span>Observe no desenho que a <\/b><\/span><\/span><\/span>coroa <\/b><\/span><\/span><\/span>da bicicleta \u00e9 maior que a <\/b><\/span><\/span><\/span>catraca.<\/b><\/span><\/span><\/span> Como o pedal fica preso na coroa, quando ele d\u00e1 uma volta completa, a coroa faz o mesmo. Mas\u2026 <\/b><\/span><\/span><\/span>numa pedalada <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

completa, <\/b><\/span><\/span><\/span>a catraca d\u00e1 algumas voltas a mais por ser menor que a coroa.<\/b><\/span><\/span><\/span> Isso faz com que os pneus tamb\u00e9m girem mais r\u00e1pido que a coroa, <\/b><\/span><\/span><\/span>aumentando a velocidade da bicicleta.<\/b><\/span><\/span><\/span><\/p>\n

16. <\/b><\/span><\/span><\/span>parte do funcionamento das <\/b><\/span><\/span><\/span>televis\u00f5es anal\u00f3gicas antigas \u00e9 devido \u00e0 deflex\u00e3o (desvio) de um feixe de el\u00e9trons por um campo eletromagn\u00e9tico. <\/b><\/span><\/span><\/span><\/p>\n

16. Correta.<\/b><\/span><\/span><\/span><\/p>\n

32. <\/b><\/span><\/span><\/span>quando voc\u00ea fala com algu\u00e9m ao <\/b><\/span><\/span><\/span>telefone<\/b><\/span><\/span><\/span>, as <\/b><\/span><\/span><\/span>ondas eletromagn\u00e9ticas<\/b><\/span><\/span><\/span> da sua voz se propagam atrav\u00e9s da <\/b><\/span><\/span><\/span>rede telef\u00f4nica<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

32. Falsa \"\" <\/b><\/span><\/span><\/span>Sua voz emite <\/b><\/span><\/span><\/span>ondas mec\u00e2nicas longitudinais<\/b><\/span><\/span><\/span> e as ondas <\/b><\/span><\/span><\/span>eletromagn\u00e9ticas se propagam pelo ar. <\/b><\/span><\/span><\/span><\/p>\n

64. <\/b><\/span><\/span><\/span>dentro de um <\/b><\/span><\/span><\/span>aspirador de p\u00f3, a press\u00e3o do ar \u00e9 menor do que na parte externa<\/b><\/span><\/span><\/span>, fazendo com que as part\u00edculas de sujeira sejam sugadas <\/b><\/span><\/span><\/span>para seu interior. <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

64. Correta \"\" A press\u00e3o<\/b><\/span><\/span><\/span> externa (maior) empurra o ar e as part\u00edculas para dentro do aspirador onde <\/b><\/span><\/span><\/span>se faz a press\u00e3o ser menor.<\/b><\/span><\/span><\/span><\/p>\n

R- 89<\/b><\/span><\/span><\/span><\/p>\n

02- <\/b><\/span><\/span><\/span>01.<\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>vetor campo magn\u00e9tico<\/b><\/span><\/span><\/span> em cada ponto <\/b><\/span><\/span><\/span>\u00e9 perpendicular \u00e0 linha de campo magn\u00e9tico<\/b><\/span><\/span><\/span> que passa por este ponto<\/b><\/span><\/span><\/span><\/p>\n

01. Falsa \"\" <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>vetor campo magn\u00e9tico<\/b><\/span><\/span><\/span> em cada ponto <\/b><\/span><\/span><\/span>\u00e9 <\/b><\/span><\/span><\/span>tangente <\/b><\/span><\/span><\/span>\u00e0 linha de campo magn\u00e9tico<\/b><\/span><\/span><\/span> que passa por este ponto<\/b><\/span><\/span><\/span><\/p>\n

02. <\/b><\/span><\/span><\/span>as<\/b><\/span><\/span><\/span>l inhas de campo magn\u00e9tico<\/b><\/span><\/span><\/span> s\u00e3o <\/b><\/span><\/span><\/span>cont\u00ednuas<\/b><\/span><\/span><\/span>, atravessando a barra magn\u00e9tica. <\/b><\/span><\/span><\/span><\/p>\n

02. Correta \"\" <\/b><\/span><\/span><\/span>S\u00e3o sempre <\/b><\/span><\/span><\/span>linhas fechadas e cont\u00ednuas<\/b><\/span><\/span><\/span> e por isso nunca se cruzam. Fora do \u00edm\u00e3, as linhas <\/b><\/span><\/span><\/span>saem do p\u00f3lo norte e se dirigem para o p\u00f3lo sul;<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Dentro do \u00edm\u00e3, as linhas s\u00e3o <\/b><\/span><\/span><\/span>orientadas do p\u00f3lo sul para o p\u00f3lo norte.<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>linhas de campo magn\u00e9tico<\/b><\/span><\/span><\/span> nunca se cruzam. <\/b><\/span><\/span><\/span><\/p>\n

04. Correta \"\"<\/b><\/span><\/span><\/span> Veja 02.<\/b><\/span><\/span><\/span><\/p>\n

08. <\/b><\/span><\/span><\/span>por conven\u00e7\u00e3o, as linhas de campo magn\u00e9tico <\/b><\/span><\/span><\/span>\u201csaem\u201d do polo sul e \u201centram\u201d no polo norte.<\/b><\/span><\/span><\/span><\/p>\n

08. Falsa \"\"<\/b><\/span><\/span><\/span> Veja 02.<\/b><\/span><\/span><\/span><\/p>\n

16. <\/b><\/span><\/span><\/span>as regi\u00f5es com <\/b><\/span><\/span><\/span>menor densidade<\/b><\/span><\/span><\/span> de linhas de campo magn\u00e9tico pr\u00f3ximas <\/b><\/span><\/span><\/span>indicam um campo magn\u00e9tico mais intenso<\/b><\/span><\/span><\/span><\/p>\n

16. Falsa \"\" Perto dos p\u00f3los<\/b><\/span><\/span><\/span>, onde o <\/b><\/span><\/span><\/span>campo magn\u00e9tico\u00a0\"\"\u00a0tem maior intensidade<\/b><\/span><\/span><\/span>, a <\/b><\/span><\/span><\/span>concentra\u00e7\u00e3o<\/b><\/span><\/span><\/span> das <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

linhas de <\/b><\/span><\/span><\/span>indu\u00e7\u00e3o \u00e9 maior<\/b><\/span><\/span><\/span>, conforme voc\u00ea pode observar na figura.<\/b><\/span><\/span><\/span><\/p>\n

32. quebrar um \u00edm\u00e3 em forma de barra<\/b><\/span><\/span><\/span> \u00e9 uma maneira simples de obter <\/b><\/span><\/span><\/span>dois p\u00f3los magn\u00e9ticos isolados<\/b><\/span><\/span><\/span><\/p>\n

32. Falsa \"\"I nseparabilidade dos p\u00f3los<\/b><\/span><\/span><\/span> \u2013 Se voc\u00ea <\/b><\/span><\/span><\/span>quebrar <\/b><\/span><\/span><\/span>um im\u00e3 e em seguida continuar <\/b><\/span><\/span><\/span>dividindo<\/b><\/span><\/span><\/span> os im\u00e3s resultantes, voc\u00ea observar\u00e1 que <\/b><\/span><\/span><\/span>cada peda\u00e7o partido<\/b><\/span><\/span><\/span> continuar\u00e1 sendo um <\/b><\/span><\/span><\/span>novo im\u00e3<\/b><\/span><\/span><\/span> com <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

dois p\u00f3los, Norte e Sul<\/b><\/span><\/span><\/span> de maneira que cada peda\u00e7o atraia o outro.\u00a0<\/b><\/span><\/span><\/span>N\u00e3o existem p\u00f3los isolados.<\/b><\/span><\/span><\/span><\/p>\n

64. cargas el\u00e9tricas<\/b><\/span><\/span><\/span> em repouso <\/b><\/span><\/span><\/span>n\u00e3o <\/b><\/span><\/span><\/span>interagem com o campo magn\u00e9tico. <\/b><\/span><\/span><\/span><\/p>\n

64. Correta \"\" <\/b><\/span><\/span><\/span>carga <\/b><\/span><\/span><\/span>em repouso (V=0) <\/b><\/span><\/span><\/span>ou lan\u00e7ada com velocidade\u00a0\"\"\u00a0paralelamente \u00e0s linhas de <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

indu\u00e7\u00e3o de um campo magn\u00e9tico uniforme\u00a0\"\", <\/b><\/span><\/span><\/span>n\u00e3o est\u00e3o sujeitas a for\u00e7a magn\u00e9tica.<\/b><\/span><\/span><\/span>\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

R- 70<\/b><\/span><\/span><\/span><\/p>\n

03- <\/b><\/span><\/span><\/span>01. <\/b><\/span><\/span><\/span>para que <\/b><\/span><\/span><\/span>todo o sistema<\/b><\/span><\/span><\/span> (estrutura, guindaste e bloco) esteja em <\/b><\/span><\/span><\/span>equil\u00edbrio<\/b><\/span><\/span><\/span>, \u00e9 necess\u00e1rio que a <\/b><\/span><\/span><\/span>soma dos momentos seja zero,\u2211 M = 0, assim como a soma das for\u00e7as, \u2211F = 0 .<\/b><\/span><\/span><\/span><\/p>\n

01. Correta\"\"<\/b><\/span><\/span><\/span> s\u00e3o as condi\u00e7\u00f5es para o <\/b><\/span><\/span><\/span>equil\u00edbrio de rota\u00e7\u00e3o<\/b><\/span><\/span><\/span> (<\/b><\/span><\/span><\/span>\u2211 M = 0) e equil\u00edbrio de transla\u00e7\u00e3o (\u2211F <\/b><\/span><\/span><\/span><\/p>\n

= 0)<\/b><\/span><\/span><\/span><\/p>\n

02. <\/b><\/span><\/span><\/span>a altura <\/b><\/span><\/span><\/span>do bloco suspenso<\/b><\/span><\/span><\/span> pelo guindaste <\/b><\/span><\/span><\/span>influencia<\/b><\/span><\/span><\/span> o seu torque em rela\u00e7\u00e3o ao <\/b><\/span><\/span><\/span>pilar A ou ao pilar C. <\/b><\/span><\/span><\/span><\/p>\n

02. Falsa \"\"<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>altura n\u00e3o influi no torque<\/b><\/span><\/span><\/span>(momento) influindo apenas a <\/b><\/span><\/span><\/span>for\u00e7a aplicada na estrutura e a dist\u00e2ncia horizontal dessa for\u00e7a ao p\u00f3lo (eixo de rota\u00e7\u00e3o).<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>\u00e0 medida que o <\/b><\/span><\/span><\/span>guindaste se desloca em dire\u00e7\u00e3o ao pilarB<\/b><\/span><\/span><\/span>, a <\/b><\/span><\/span><\/span>for\u00e7a<\/b><\/span><\/span><\/span> de rea\u00e7\u00e3o dos <\/b><\/span><\/span><\/span>pilares A e C aumenta e diminui, respectivamente<\/b><\/span><\/span><\/span><\/p>\n

04. Correta \"\"<\/b><\/span><\/span><\/span> \u00e0 medida que o <\/b><\/span><\/span><\/span>guindaste se desloca para a esquerdaseu peso comprime<\/b><\/span><\/span><\/span> mais o pilar <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A<\/b><\/span><\/span><\/span> e <\/b><\/span><\/span><\/span>diminui a compress\u00e3o do pilar C<\/b><\/span><\/span><\/span> (veja figura).<\/b><\/span><\/span><\/span><\/p>\n

08. <\/b><\/span><\/span><\/span>supondo que o <\/b><\/span><\/span><\/span>bloco suspenso<\/b><\/span><\/span><\/span> esteja a <\/b><\/span><\/span><\/span>20,0 m do pilar C<\/b><\/span><\/span><\/span>, as <\/b><\/span><\/span><\/span>for\u00e7as de rea\u00e7\u00e3o nos pilares A e Cs\u00e3o, respectivamente, 121,5.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span> N e 93,5.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span> N.<\/b><\/span><\/span><\/span><\/p>\n

08. Correta \"\" <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>equil\u00edbrio de transla\u00e7\u00e3o<\/b><\/span><\/span><\/span> as <\/b><\/span><\/span><\/span>for\u00e7as verticais devem se anular<\/b><\/span><\/span><\/span> (veja figura) \"\"N<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> + N<\/b><\/span><\/span><\/span>C<\/b><\/span><\/span><\/sub><\/span><\/p>\n

\"\"<\/p>\n

=200.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span> + 15.10<\/b><\/span><\/span><\/span>4\"\"<\/b><\/span><\/span><\/sup><\/span>N<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> + N<\/b><\/span><\/span><\/span>C<\/b><\/span><\/span><\/sub><\/span> = 215.10<\/b><\/span><\/span><\/span>4\"\"<\/b><\/span><\/span><\/sup><\/span> observe <\/b><\/span><\/span><\/span>que somando os valores fornecidos<\/b><\/span><\/span><\/span> que s\u00e3o 121,5.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span> + 93,5.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span> voc\u00ea <\/b><\/span><\/span><\/span>obter\u00e1 215.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

16. inserir um novo ponto de sustenta\u00e7\u00e3o<\/b><\/span><\/span><\/span> da estrutura no <\/b><\/span><\/span><\/span>pilar B<\/b><\/span><\/span><\/span> n\u00e3o altera as <\/b><\/span><\/span><\/span>for\u00e7as de rea\u00e7\u00e3o nos pilares A e C. <\/b><\/span><\/span><\/span><\/p>\n

16. Falsa \"\" <\/b><\/span><\/span><\/span>se voc\u00ea <\/b><\/span><\/span><\/span>aumentar a altura do pilar B<\/b><\/span><\/span><\/span> estar\u00e1 <\/b><\/span><\/span><\/span>aumentando a rea\u00e7\u00e3o no pilar A que influenciar\u00e1 tamb\u00e9m na rea\u00e7\u00e3o do pilar C.<\/b><\/span><\/span><\/span><\/p>\n

32.<\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>for\u00e7as de rea\u00e7\u00e3o nos pilares A e C<\/b><\/span><\/span><\/span> se alteram durante a <\/b><\/span><\/span><\/span>subida do bloco<\/b><\/span><\/span><\/span>, em velocidade constante, pelo guindaste.<\/b><\/span><\/span><\/span><\/p>\n

32. Falsa \"\"<\/b><\/span><\/span><\/span> as <\/b><\/span><\/span><\/span>for\u00e7as de rea\u00e7\u00e3o nos pilares A e C<\/b><\/span><\/span><\/span> s\u00f3 ir\u00e3o variar se voc\u00ea <\/b><\/span><\/span><\/span>modificar a dist\u00e3ncia horizontal <\/b><\/span><\/span><\/span>do sistema guindaste-bloco.<\/b><\/span><\/span><\/span><\/p>\n

R- 13<\/b><\/span><\/span><\/span><\/p>\n

04- <\/b><\/span><\/span><\/span>Trata-se do <\/b><\/span><\/span><\/span>efeito Doppler<\/b><\/span><\/span><\/span> e, se voc\u00ea n\u00e3o domina a teoria ela est\u00e1 a seguir:<\/b><\/span><\/span><\/span><\/p>\n

Refere-se \u00e0 <\/b><\/span><\/span><\/span>varia\u00e7\u00e3o da freq\u00fc\u00eancia<\/b><\/span><\/span><\/span> notada por um observador quando a dist\u00e2ncia entre ele e uma fonte de ondas est\u00e1 <\/b><\/span><\/span><\/span>aumentando ou diminuindo.<\/b><\/span><\/span><\/span><\/p>\n

Na <\/b><\/span><\/span><\/span>aproxima\u00e7\u00e3o<\/b><\/span><\/span><\/span> entre fonte e observador, o mesmo <\/b><\/span><\/span><\/span>perceber\u00e1<\/b><\/span><\/span><\/span> o som emitido pela fonte <\/b><\/span><\/span><\/span>mais agudo<\/b><\/span><\/span><\/span> (<\/b><\/span><\/span><\/span>maior freq\u00fc\u00eancia, recebe maior n\u00famero de frentes de onda na unidade de tempo)<\/b><\/span><\/span><\/span> do que perceberia se fonte e observador estivessem <\/b><\/span><\/span><\/span>parados<\/b><\/span><\/span><\/span>. Nesse caso, o comprimento de onda aparente percebido pelo observador ser\u00e1 menor que o comprimento da onda emitido pela fonte (observador O1\u00a0da figura abaixo).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

No <\/b><\/span><\/span><\/span>afastamento entre fonte e observador<\/b><\/span><\/span><\/span>, o mesmo perceber\u00e1 o som emitido pela fonte <\/b><\/span><\/span><\/span>mais grave (menor freq\u00fc\u00eancia, recebe menor n\u00famero de frentes de onda na unidade de tempo)<\/b><\/span><\/span><\/span> do que perceberia se fonte e observador estivessem <\/b><\/span><\/span><\/span>parados.<\/b><\/span><\/span><\/span> Nesse caso, o comprimento de onda aparente percebido pelo observador ser\u00e1 maior que o comprimento da onda emitido pela fonte (observador O2\u00a0da figura acima).<\/b><\/span><\/span><\/span><\/p>\n

Observe que o <\/b><\/span><\/span><\/span>motorista <\/b><\/span><\/span><\/span>da ambul\u00e2ncia n\u00e3o percebe <\/b><\/span><\/span><\/span>nenhuma altera\u00e7\u00e3o no som<\/b><\/span><\/span><\/span> emitido pela sirene, pois eles se <\/b><\/span><\/span><\/span>movem juntos e a velocidade relativa entre eles \u00e9 nula.<\/b><\/span><\/span><\/span><\/p>\n

Se <\/b><\/span><\/span><\/span>houver vento<\/b><\/span><\/span><\/span>, o mesmo em movimento altera apenas a velocidade da onda, mas <\/b><\/span><\/span><\/span>n\u00e3o altera a frequ\u00eancia do som.<\/b><\/span><\/span><\/span><\/p>\n

01. <\/b><\/span><\/span><\/span>a anota\u00e7\u00e3o <\/b><\/span><\/span><\/span>I est\u00e1 correta<\/b><\/span><\/span><\/span> porque, quando o carro de pol\u00edcia se <\/b><\/span><\/span><\/span>aproxima,<\/b><\/span><\/span><\/span> o comprimento de onda do som da sirene \u00e9 aparentemente encurtado e a <\/b><\/span><\/span><\/span>frequ\u00eancia percebida \u00e9 maior.<\/b><\/span><\/span><\/span><\/p>\n

01. Correta <\/b><\/span><\/span><\/span><\/p>\n

02. <\/b><\/span><\/span><\/span>a anota\u00e7\u00e3o <\/b><\/span><\/span><\/span>II est\u00e1 correta<\/b><\/span><\/span><\/span> porque, quando o carro <\/b><\/span><\/span><\/span>se afasta<\/b><\/span><\/span><\/span>, o comprimento de onda do som da buzina <\/b><\/span><\/span><\/span>n\u00e3o se altera<\/b><\/span><\/span><\/span>, apenas <\/b><\/span><\/span><\/span>diminui o n\u00famero de frentes de onda<\/b><\/span><\/span><\/span> que passam por Pedro.<\/b><\/span><\/span><\/span><\/p>\n

02. Falsa<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>a anota\u00e7\u00e3o <\/b><\/span><\/span><\/span>III est\u00e1 incorreta<\/b><\/span><\/span><\/span> porque a <\/b><\/span><\/span><\/span>velocidade relativa <\/b><\/span><\/span><\/span>entre o carro de bombeiros e Pedro <\/b><\/span><\/span><\/span>n\u00e3o\u00e9 zero.<\/b><\/span><\/span><\/span><\/p>\n

04. Falsa<\/b><\/span><\/span><\/span><\/p>\n

08. <\/b><\/span><\/span><\/span>a anota\u00e7\u00e3o <\/b><\/span><\/span><\/span>IV est\u00e1 correta<\/b><\/span><\/span><\/span> porque o vento em movimento altera apenas a velocidade da onda, mas <\/b><\/span><\/span><\/span>n\u00e3o altera a frequ\u00eancia<\/b><\/span><\/span><\/span> do som da sirene do carro de bombeiros em repouso.<\/b><\/span><\/span><\/span><\/p>\n

08. Correta<\/b><\/span><\/span><\/span><\/p>\n

16. <\/b><\/span><\/span><\/span>a anota\u00e7\u00e3o <\/b><\/span><\/span><\/span>II est\u00e1 correta<\/b><\/span><\/span><\/span> porque, quando o carro<\/b><\/span><\/span><\/span>se afasta<\/b><\/span><\/span><\/span>, o buzina\u00e7o provoca ondas de choque que alteram a freq\u00fc\u00eancia do som emitido pela sirene.<\/b><\/span><\/span><\/span><\/p>\n

16. Falsa<\/b><\/span><\/span><\/span><\/p>\n

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

05- <\/b><\/span><\/span><\/span>01 <\/b><\/span><\/span><\/span>o m\u00f3dulo da <\/b><\/span><\/span><\/span>velocidade m\u00e9dia<\/b><\/span><\/span><\/span> de <\/b><\/span><\/span><\/span>Tiago \u00e9 0,625 m\/s.<\/b><\/span><\/span><\/span><\/p>\n

01. Correta \"\" <\/b><\/span><\/span><\/span>Veja na figura abaixo os <\/b><\/span><\/span><\/span>deslocamentos <\/b><\/span><\/span><\/span>nos respectivos trechos.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Trecho 1 \"\" <\/b><\/span><\/span><\/span>V = \u2206S<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\/\u2206t<\/b><\/span><\/span><\/span>1\"\"<\/b><\/span><\/span><\/sub><\/span>0,875 = 300\/\/\u2206t<\/b><\/span><\/span><\/span>1\"\"<\/b><\/span><\/span><\/sub><\/span>\u2206t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span> = 342,85s.<\/b><\/span><\/span><\/span><\/p>\n

Trecho 2 \"\" <\/b><\/span><\/span><\/span>V = \u2206S<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\/\u2206t<\/b><\/span><\/span><\/span>2\"\"<\/b><\/span><\/span><\/sub><\/span> 0,875 = 400\/\/\u2206t<\/b><\/span><\/span><\/span>2\"\"<\/b><\/span><\/span><\/sub><\/span>\u2206t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span> = 457,14s.<\/b><\/span><\/span><\/span><\/p>\n

Tempo total \"\" \u2206t<\/b><\/span><\/span><\/span> = 342,85 + 457,14 <\/b><\/span><\/span><\/span>= 800s.<\/b><\/span><\/span><\/span><\/p>\n

Velocidade m\u00e9dia \"\" <\/b><\/span><\/span><\/span>V<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span> = \u2206S\/\u2206t = 500\/800 \"\"<\/b><\/span><\/span><\/span>V<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span> = 0,625 m\/s.<\/b><\/span><\/span><\/span><\/p>\n

02.<\/b><\/span><\/span><\/span> Tiago e Jo\u00e3o realizam seus <\/b><\/span><\/span><\/span>percursos<\/b><\/span><\/span><\/span> em <\/b><\/span><\/span><\/span>tempos diferentes.<\/b><\/span><\/span><\/span><\/p>\n

02. Falsa \"\"<\/b><\/span><\/span><\/span> observe na figura que <\/b><\/span><\/span><\/span>Jo\u00e3o percorreu \u2206S = 1000m com V<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span> = 1,25 m\/s\"\"<\/b><\/span><\/span><\/span>V<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span> = \u2206S\/\u2206t \"\"<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

1,25 = 1000\/\u2206t \"\"<\/b><\/span><\/span><\/span>\u2206t<\/b><\/span><\/span><\/span> = 1000\/1,25 <\/b><\/span><\/span><\/span>= 800s (mesmo tempo de percurso que o de Tiago)<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/span>deslocamento de Tiago \u00e9 de 700 m.<\/b><\/span><\/span><\/span><\/p>\n

04. Falsa \"\" \u00e9 de <\/b><\/span><\/span><\/span>500m (veja 01).<\/b><\/span><\/span><\/span><\/p>\n

08<\/b><\/span><\/span><\/span>. a <\/b><\/span><\/span><\/span>velocidade escalar m\u00e9dia<\/b><\/span><\/span><\/span> de Jo\u00e3o \u00e9 de <\/b><\/span><\/span><\/span>1,75 m\/s.<\/b><\/span><\/span><\/span><\/p>\n

08. Correta \"\" d<\/b><\/span><\/span><\/span> = 600 + 800 <\/b><\/span><\/span><\/span>= 1400 m\"\"\u2206t= 800s\"\"V<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span> =dist\u00e2ncia efetivamente percorrida\/intervalo de tempo = 1400\/800 \"\"V<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span>= 1,75 m\/s.<\/b><\/span><\/span><\/span><\/p>\n

16. <\/b><\/span><\/span><\/span>o m\u00f3dulo do <\/b><\/span><\/span><\/span>deslocamento de Jo\u00e3o em rela\u00e7\u00e3o a Tiago \u00e9 1500 m.<\/b><\/span><\/span><\/span><\/p>\n

16. Correta \"\" <\/b><\/span><\/span><\/span>veja figura abaixo:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

32. <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>velocidade<\/b><\/span><\/span><\/span> de Jo\u00e3o em rela\u00e7\u00e3o a Tiago \u00e9 de <\/b><\/span><\/span><\/span>0,625 m\/s.<\/b><\/span><\/span><\/span><\/p>\n

32. Falsa \"\" <\/b><\/span><\/span><\/span>essa \u00e9 a <\/b><\/span><\/span><\/span>velocidade m\u00e9dia de Tiago.<\/b><\/span><\/span><\/span><\/p>\n

R- 25<\/b><\/span><\/span><\/span><\/p>\n

06- <\/b><\/span><\/span><\/span>01. <\/b><\/span><\/span><\/span>para carregar o <\/b><\/span><\/span><\/span>celular<\/b><\/span><\/span><\/span>, a tens\u00e3o do <\/b><\/span><\/span><\/span>gerador<\/b><\/span><\/span><\/span> tem que ser no <\/b><\/span><\/span><\/span>m\u00ednimo igual \u00e0 tens\u00e3o do receptor<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

01. Falsa \"\" <\/b><\/span><\/span><\/span>para carregar o <\/b><\/span><\/span><\/span>celular<\/b><\/span><\/span><\/span>, a tens\u00e3o do <\/b><\/span><\/span><\/span>gerador (computador)<\/b><\/span><\/span><\/span> tem que ser maior que a <\/b><\/span><\/span><\/span>tens\u00e3o do receptor (celular)<\/b><\/span><\/span><\/span>. <\/b><\/span><\/span><\/span><\/p>\n

02. <\/b><\/span><\/span><\/span>quando <\/b><\/span><\/span><\/span>desconectamos<\/b><\/span><\/span><\/span> o celular do computador, equivale a <\/b><\/span><\/span><\/span>abrir a chave 1.<\/b><\/span><\/span><\/span><\/p>\n

02. Correta \"\" <\/b><\/span><\/span><\/span>abrindo a <\/b><\/span><\/span><\/span>chave 1<\/b><\/span><\/span><\/span> voc\u00ea estar\u00e1 desconectando o computador do celular, <\/b><\/span><\/span><\/span>n\u00e3o havendo<\/b><\/span><\/span><\/span> passagem de corrente el\u00e9trica de um para o outro.<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>corrente el\u00e9trica<\/b><\/span><\/span><\/span> que percorre a <\/b><\/span><\/span><\/span>bateria do celular<\/b><\/span><\/span><\/span> quando a chave 1 est\u00e1 <\/b><\/span><\/span><\/span>fechada \u00e9 de 0,4A.<\/b><\/span><\/span><\/span><\/p>\n

04. Correta \"\"<\/b><\/span><\/span><\/span> com a chave 1 fechada o enunciado fornece que a <\/b><\/span><\/span><\/span>tens\u00e3o de sa\u00edda do computador<\/b><\/span><\/span><\/span> \u00e9 <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

de<\/b><\/span><\/span><\/span> U = 5V<\/b><\/span><\/span><\/span> que \u00e9 a <\/b><\/span><\/span><\/span>mesma tens\u00e3o<\/b><\/span><\/span><\/span> que a dos <\/b><\/span><\/span><\/span>terminais do celular (est\u00e3o em paralelo).<\/b><\/span><\/span><\/span><\/p>\n

No celular a corrente \u00e9 i<\/b><\/span><\/span><\/span>c\"\" <\/b><\/span><\/span><\/sub><\/span>U<\/b><\/span><\/span><\/span>c<\/b><\/span><\/span><\/sub><\/span> = \u03b5<\/b><\/span><\/span><\/span>c<\/b><\/span><\/span><\/sub><\/span>+r<\/b><\/span><\/span><\/span>c<\/b><\/span><\/span><\/sub><\/span>.i<\/b><\/span><\/span><\/span>c\"\"<\/b><\/span><\/span><\/sub><\/span> 5 = 4,6 + 1.i<\/b><\/span><\/span><\/span>c\"\" <\/b><\/span><\/span><\/sub><\/span>i<\/b><\/span><\/span><\/span>c<\/b><\/span><\/span><\/sub><\/span> = 0,4 A.<\/b><\/span><\/span><\/span><\/p>\n

08. <\/b><\/span><\/span><\/span>para a resist\u00eancia <\/b><\/span><\/span><\/span>R igual a 50,0\u2126,<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>corrente <\/b><\/span><\/span><\/span>que percorre o celular quando <\/b><\/span><\/span><\/span>desconectado do computador \u00e9 de aproximadamente 0,09A.<\/b><\/span><\/span><\/span><\/p>\n

\"\"16.<\/b><\/span><\/span><\/span> de acordo com o circuito, o <\/b><\/span><\/span><\/span>resistor R sempre estar\u00e1 associado em paralelo com r<\/b><\/span><\/span><\/span>b<\/b><\/span><\/span><\/sub><\/span>. <\/b><\/span><\/span><\/span><\/p>\n

16. Falsa \"\" <\/b><\/span><\/span><\/span>se a <\/b><\/span><\/span><\/span>chave 1<\/b><\/span><\/span><\/span> estiver <\/b><\/span><\/span><\/span>desconectada<\/b><\/span><\/span><\/span> eles estar\u00e3o em <\/b><\/span><\/span><\/span>s\u00e9rie<\/b><\/span><\/span><\/span> (veja 08). <\/b><\/span><\/span><\/span><\/p>\n

32.<\/b><\/span><\/span><\/span> se o <\/b><\/span><\/span><\/span>celular estiver ligado e conectado ao computador<\/b><\/span><\/span><\/span>, tanto o computador quanto a bateria do celular ser\u00e3o os <\/b><\/span><\/span><\/span>geradores<\/b><\/span><\/span><\/span> do circuito.<\/b><\/span><\/span><\/span><\/p>\n

32. Falsa<\/b><\/span><\/span><\/span> \"\" o <\/b><\/span><\/span><\/span>gerador \u00e9 o computador<\/b><\/span><\/span><\/span>, que est\u00e1 carregando o celular.<\/b><\/span><\/span><\/span><\/p>\n

R- 14<\/b><\/span><\/span><\/span><\/p>\n

07- <\/b><\/span><\/span><\/span>01. <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>reflex\u00e3o <\/b><\/span><\/span><\/span>da luz \u00e9 classificada de duas formas: a <\/b><\/span><\/span><\/span>reflex\u00e3o difusa e a reflex\u00e3o especular<\/b><\/span><\/span><\/span>, que s\u00f3 ocorre em <\/b><\/span><\/span><\/span>superf\u00edcies planas.<\/b><\/span><\/span><\/span><\/p>\n

01. Falsa \"\" <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>reflex\u00e3o <\/b><\/span><\/span><\/span>da luz \u00e9 classificada de duas formas: a <\/b><\/span><\/span><\/span>reflex\u00e3o difusa e a reflex\u00e3o especular<\/b><\/span><\/span><\/span>, que s\u00f3 ocorre em <\/b><\/span><\/span><\/span>qualquer tipo de superf\u00edcie, desde que seja refletora.<\/b><\/span><\/span><\/span><\/p>\n

02. <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>refra\u00e7\u00e3o <\/b><\/span><\/span><\/span>da luz \u00e9 caracterizada pelo <\/b><\/span><\/span><\/span>desvio da luz ao mudar de meio com refring\u00eancias distintas.<\/b><\/span><\/span><\/span><\/p>\n

02. Falsa \"\" <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>refra\u00e7\u00e3o <\/b><\/span><\/span><\/span>da luz \u00e9 caracterizada pela varia\u00e7\u00e3o da velocidade<\/b><\/span><\/span><\/span> da luz ao mudar de meio com refring\u00eancias distintas.<\/b><\/span><\/span><\/span>Quando a incid\u00eancia <\/b><\/span><\/span><\/span>\u00e9 perpendicular \u00e0 superf\u00edcie de separa\u00e7\u00e3o n\u00e3o ocorre desvio.<\/b><\/span><\/span><\/span><\/p>\n

04. <\/b><\/span><\/span><\/span>a luz incide no <\/b><\/span><\/span><\/span>pentaprisma<\/b><\/span><\/span><\/span>e sofre <\/b><\/span><\/span><\/span>duas reflex\u00f5es<\/b><\/span><\/span><\/span> antes de emergir. Estas reflex\u00f5es s\u00e3o chamadas de <\/b><\/span><\/span><\/span>reflex\u00f5es totais, pois duas condi\u00e7\u00f5es est\u00e3o sendo satisfeitas<\/b><\/span><\/span><\/span>: a luz est\u00e1 no <\/b><\/span><\/span><\/span>meio maisrefringente<\/b><\/span><\/span><\/span> e o <\/b><\/span><\/span><\/span>\u00e2ngulo de incid\u00eancia \u00e9 maior que o \u00e2ngulo limite.<\/b><\/span><\/span><\/span><\/p>\n

04. Correta \"\" <\/b><\/span><\/span><\/span>Condi\u00e7\u00f5es para que <\/b><\/span><\/span><\/span>ocorra reflex\u00e3o total:<\/b><\/span><\/span><\/span><\/p>\n

1<\/b><\/span><\/span><\/span>a<\/b><\/span><\/span><\/sup><\/span>\u00a0\u2013 A luz deve se propagar do <\/b><\/span><\/span><\/span>meio mais refringente (maior \u00edndice) para o meio menos refringente (menor \u00edndice)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

2<\/b><\/span><\/span><\/span>a<\/b><\/span><\/span><\/sup><\/span>\u00a0\u2013 A luz deve <\/b><\/span><\/span><\/span>incidir com \u00e2ngulo sempre maior que o \u00e2ngulo limite L.<\/b><\/span><\/span><\/span><\/p>\n

08.<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/span>conjunto de lentes da objetiva<\/b><\/span><\/span><\/span> \u00e9 formado por <\/b><\/span><\/span><\/span>lentes divergentes<\/b><\/span><\/span><\/span>, pois somente elas formam <\/b><\/span><\/span><\/span>imagens reais, que s\u00e3o projetadas.<\/b><\/span><\/span><\/span><\/p>\n

08. Falsa\"\"<\/b><\/span><\/span><\/span>quem forma <\/b><\/span><\/span><\/span>imagens reais, que podem ser projetadas<\/b><\/span><\/span><\/span> s\u00e3o lentes <\/b><\/span><\/span><\/span>convergentes.<\/b><\/span><\/span><\/span> As <\/b><\/span><\/span><\/span>divergentes<\/b><\/span><\/span><\/span> s\u00f3 formam imagens <\/b><\/span><\/span><\/span>virtuais, que n\u00e3o podem ser projetadas.<\/b><\/span><\/span><\/span><\/p>\n

16. <\/b><\/span><\/span><\/span>a imagem projetada no sensor<\/b><\/span><\/span><\/span> \u00e9 real, direita e menor.<\/b><\/span><\/span><\/span> Isto garante que ela possa ser vista com a <\/b><\/span><\/span><\/span>mesma orienta\u00e7\u00e3o, tanto pela ocular quanto pelo visor LCD.<\/b><\/span><\/span><\/span><\/p>\n

16. Falsa \"\" a imagem projetada no sensor<\/b><\/span><\/span><\/span> \u00e9 real, <\/b><\/span><\/span><\/span>invertida<\/b><\/span><\/span><\/span> e menor.<\/b><\/span><\/span><\/span> Isto garante que ela possa ser vista <\/b><\/span><\/span><\/span>invertida em rela\u00e7\u00e3o ao objeto, tanto pela ocular quanto pelo visor LCD.<\/b><\/span><\/span><\/span><\/p>\n

32. <\/b><\/span><\/span><\/span>pela <\/b><\/span><\/span><\/span>figura,<\/b><\/span><\/span><\/span> podemos observar que o <\/b><\/span><\/span><\/span>raio de luz<\/b><\/span><\/span><\/span> que <\/b><\/span><\/span><\/span>incide<\/b><\/span><\/span><\/span> no pentaprisma <\/b><\/span><\/span><\/span>cruza <\/b><\/span><\/span><\/span>com o raio de luz que <\/b><\/span><\/span><\/span>ir\u00e1 emergir.<\/b><\/span><\/span><\/span> O <\/b><\/span><\/span><\/span>princ\u00edpio da independ\u00eancia dos raios luminosos<\/b><\/span><\/span><\/span> garante que este \u201cencontro\u201d <\/b><\/span><\/span><\/span>n\u00e3o interfira<\/b><\/span><\/span><\/span> na imagem vista pelo observador pela ocular.<\/b><\/span><\/span><\/span><\/p>\n

32. Correta<\/b><\/span><\/span><\/span><\/p>\n

\u00a0<\/span><\/span><\/span><\/a><\/h2>\n

Voltar para os exerc\u00edcios.<\/span><\/a><\/h2>\n","protected":false},"excerpt":{"rendered":"

RESOLU\u00c7\u00d5ES 01- 01. nas l\u00e2mpadas incandescentes ocorre o efeito Joule, que provoca o aquecimento do filamento de tungst\u00eanio (resistor). 01. Correta As l\u00e2mpadas incandescentes utilizam um fio de tungst\u00eanio encerrado num bulbo de vidro. Esse fio tem di\u00e2metro inferior a 0,1 mm e \u00e9 enrolado segundo uma h\u00e9lice cil\u00edndrica. Passando corrente el\u00e9trica no filamento, ele se aquece a uma temperatura<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":692,"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-694","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/694","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=694"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/694\/revisions"}],"predecessor-version":[{"id":695,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/694\/revisions\/695"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/692"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=694"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}