{"id":3390,"date":"2017-11-05T23:22:52","date_gmt":"2017-11-05T23:22:52","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3390"},"modified":"2024-09-04T14:15:05","modified_gmt":"2024-09-04T14:15:05","slug":"vestibulares-recentes-resolucao-comentada-fisica-moderna-2017-2016-2015","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/vestibulares-recentes\/fisica-moderna\/fisica-moderna-2017-2016-2015\/vestibulares-recentes-resolucao-comentada-fisica-moderna-2017-2016-2015\/","title":{"rendered":"Vestibulares Recentes \u2013 Resolu\u00e7\u00e3o Comentada F\u00cdSICA MODERNA \u2013 2017 \u2013 2016 \u2013 2015"},"content":{"rendered":"

Vestibulares Recentes \u2013 Resolu\u00e7\u00e3o Comentada<\/span><\/span><\/span><\/p>\n

F\u00cdSICA MODERNA \u2013 2017 \u2013 2016 \u2013 2015<\/span><\/span><\/span><\/p>\n

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

\u00a0<\/span>a. Falsa\u00a0\"\"<\/b><\/span><\/span>\u00a0O\u00a0<\/b><\/span><\/span>efeito fotoel\u00e9trico ocorre quando\u00a0a luz\u00a0(onda eletromagn\u00e9tica, radia\u00e7\u00e3o eletromagn\u00e9tica)\u00a0de frequ\u00eancia suficientemente alta incide sobre a superf\u00edcie de um metal, ela pode retirar el\u00e9trons do mesmo.<\/b><\/span><\/span><\/span><\/span><\/p>\n

b. Falsa\u00a0\"\"<\/b><\/span><\/span>\u00a0Nas l\u00e2mpadas\u00a0<\/b><\/span><\/span>incandescentes a emiss\u00e3o de luz ocorre devido ao aquecimento de seu filamento<\/b><\/span><\/span>\u00a0por\u00a0<\/b><\/span><\/span>efeito Joule\u00a0<\/b><\/span><\/span>(choque dos el\u00e9trons da corrente el\u00e9trica com as part\u00edculas do filamento)<\/b><\/span><\/span><\/span><\/span><\/p>\n

c. Falsa\u00a0\"\"<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>N\u00e3o \u00e9 a carga el\u00e9trica\u00a0<\/b><\/span><\/span>do f\u00f3ton que \u00e9\u00a0<\/b><\/span><\/span>absorvida pelo metal, \u00e9 a energia do mesmo.<\/b><\/span><\/span><\/span><\/span><\/p>\n

d. Falsa\u00a0\"\"<\/b><\/span><\/span>\u00a0A\u00a0<\/b><\/span><\/span>fa\u00edsca<\/b><\/span><\/span>\u00a0ocorre quando o\u00a0<\/b><\/span><\/span>meio que era isolante se torna condutor\u00a0<\/b><\/span><\/span>devido \u00e0 uma\u00a0<\/b><\/span><\/span>diferen\u00e7a de potencial muito elevada.<\/b><\/span><\/span><\/span><\/span><\/p>\n

e. Correta\u00a0\"\"<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>O\u00a0efeito fotoel\u00e9trico s\u00f3 surge se o metal receber um feixe de radia\u00e7\u00e3o com\u00a0energia superior\u00a0\u00e0\u00a0energia m\u00ednima de remo\u00e7\u00e3o dos el\u00e9trons\u00a0do metal, provocando a\u00a0sua sa\u00edda das \u00f3rbitas\u00a0o que\u00a0pode ocorrer sem energia cin\u00e9tica\u00a0(se a energia da radia\u00e7\u00e3o for igual \u00e0 energia de remo\u00e7\u00e3o) ou\u00a0com energia cin\u00e9tica, (se a energia da radia\u00e7\u00e3o exceder a energia de remo\u00e7\u00e3o dos el\u00e9trons).<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

 <\/p>\n

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

 <\/p>\n

\"\"<\/p>\n

Na figura acima temos uma\u00a0<\/b><\/span><\/span>ilustra\u00e7\u00e3o do efeito fotoel\u00e9trico<\/b><\/span><\/span>, vamos analisar as alternativas. A\u00a0<\/b><\/span><\/span>energia absorvida varia para cada material analisado, sendo assim alternativa A est\u00e1 incorreta<\/b><\/span><\/span>. O efeito fotoel\u00e9trico<\/b><\/span><\/span>s\u00f3 ocorre se a frequ\u00eancia da luz incidente for maior que a frequ\u00eancia-limite, alternativa B incorreta e a C \u00e9 a correta<\/b><\/span><\/span>. A\u00a0<\/b><\/span><\/span>alternativa D est\u00e1 incorreta<\/b><\/span><\/span>, pois\u00a0<\/b><\/span><\/span>n\u00e3o s\u00e3o os n\u00facleos que escapam, s\u00e3o os el\u00e9trons que orbitam esses n\u00facleos<\/b><\/span><\/span>. Quanto\u00a0<\/b><\/span><\/span>maior a fun\u00e7\u00e3o trabalho mais energia \u00e9 necess\u00e1ria para se retirar o el\u00e9tron<\/b><\/span><\/span>, consequentemente\u00a0<\/b><\/span><\/span>maior a frequ\u00eancia de luz necess\u00e1ria, alternativa E errada<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

Equa\u00e7\u00e3o Fotoel\u00e9trica de Einstein<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n


\n<\/b><\/span><\/span>Da equa\u00e7\u00e3o W = h.f \u00a0\"\"\u00a0\u00a0f<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\u00a0= W\/h\u00a0\"\"\u00a0 f<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\u00a0\u00e9 a frequ\u00eancia m\u00ednima (frequ\u00eancia de corte) a partir da qual os el\u00e9trons s\u00e3o extra\u00eddos do metal.<\/b><\/span><\/span><\/span><\/span>\"\"<\/p>\n

Assim, nenhum el\u00e9tron \u00e9 emitido pelo metal enquanto a frequ\u00eancia da luz (f\u00f3tons) incidente n\u00e3o ultrapassar um certo limite de frequ\u00eancia, denominada frequ\u00eancia de corte (fo).<\/b><\/span><\/span><\/span><\/span><\/p>\n

f<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\u00a0=\u00a0\"\"\u00a0\"\"\u00a0<\/b><\/span><\/span>f<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\u00a0=\u00a0\"\"<\/b><\/span><\/span>\u00a0\"\"\u00a0f<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\u00a0= 1,49 Hz.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

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

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

\"\"04) Correta\u00a0\"\"<\/b><\/span><\/span>\u00a0A\u00a0<\/b><\/span><\/span>radia\u00e7\u00e3o ionizante pode impedir a reprodu\u00e7\u00e3o celular ou prejudicar este processo,\u00a0<\/b><\/span><\/span>bem como\u00a0<\/b><\/span><\/span>matar as c\u00e9lulas,\u00a0<\/b><\/span><\/span>processo conhecido\u00a0<\/b><\/span><\/span>como necrose.\u00a0<\/b><\/span><\/span>Al\u00e9m disso, este\u00a0<\/b><\/span><\/span>tipo de radia\u00e7\u00e3o\u00a0<\/b><\/span><\/span>pode\u00a0<\/b><\/span><\/span>provocar apoptose das c\u00e9lulas<\/b><\/span><\/span>, que ao\u00a0<\/b><\/span><\/span>contr\u00e1rio da necrose,\u00a0<\/b><\/span><\/span>\u00e9 a\u00a0<\/b><\/span><\/span>morte das c\u00e9lulas atingidas<\/b><\/span><\/span>, de\u00a0<\/b><\/span><\/span>forma programada pelo organismo\u00a0<\/b><\/span><\/span>para conter o<\/b><\/span><\/span>desenvolvimento de tumores.<\/b><\/span><\/span><\/span><\/span><\/p>\n

08) Correta\u00a0\"\"<\/b><\/span><\/span>\u00a0Se\u00a0<\/b><\/span><\/span>1 eV tem energia de 1.6\u00d710-16 J<\/b><\/span><\/span>, ent\u00e3o\u00a0<\/b><\/span><\/span>9\u00d7106\u00a0eV ter\u00e1 14.4\u00d710-13\u00a0J.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

16) Errada\u00a0\"\"<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>E = hf\u00a0\"\"\u00a0f<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>= E\/h\u00a0<\/b><\/span><\/span>= (40.103)\/(4.10-15) = 10.1015.103\u00a0(1\/s)\u00a0\"\"\u00a0<\/b><\/span><\/span>f = 1,0.1019\u00a0Hz<\/b><\/span><\/span><\/span><\/span><\/p>\n

R- (02, 04, 08)<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

A) S\u00e3o dados: frequ\u00eancia<\/b><\/span><\/span><\/span>\u00a0dos f\u00f3tons\u00a0<\/b><\/span><\/span><\/span>f = 1,2.10<\/b><\/span><\/span><\/span>15<\/b><\/span><\/span><\/sup><\/span>\u00a0Hz\u00a0<\/b><\/span><\/span><\/span>e\u00a0<\/b><\/span><\/span><\/span>velocidade da luz no v\u00e1cuo c = 3.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>\u00a0m\/s\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0equa\u00e7\u00e3o fundamental da ondulat\u00f3ria\u00a0<\/b><\/span><\/span><\/span>V = c =.<\/b><\/span><\/span><\/span>f\u00a0\"\"\u00a03.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>\u00a0=\u00a0.1,2.10<\/b><\/span><\/span><\/span>15<\/b><\/span><\/span><\/sup><\/span>\u00a0\"\"\u00a0 =\u00a0\"\"\u00a0= 2,5.10<\/b><\/span><\/span><\/span><\/p>\n

-7<\/b><\/span><\/span><\/sup><\/span>\u00a0= 250.10<\/b><\/span><\/span><\/span>-9<\/b><\/span><\/span><\/sup><\/span>\u00a0m\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>\u00a0= 250 nm.<\/b><\/span><\/span><\/span><\/p>\n

Energia de cada f\u00f3ton\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>W = h.f\u00a0<\/b><\/span><\/span><\/span>com\u00a0<\/b><\/span><\/span><\/span>h\u00a0<\/b><\/span><\/span><\/span>= constante de Planck\u00a0<\/b><\/span><\/span><\/span>= 6,6.10<\/b><\/span><\/span><\/span>-34J<\/b><\/span><\/span><\/sup><\/span>.s\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0W = 6,6.10-<\/b><\/span><\/span><\/span>34<\/b><\/span><\/span><\/sup><\/span>.1,2. 10<\/b><\/span><\/span><\/span>15<\/b><\/span><\/span><\/sup><\/span>\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>W = 7,92.10<\/b><\/span><\/span><\/span>-19<\/b><\/span><\/span><\/sup><\/span>\u00a0J.<\/b><\/span><\/span><\/span><\/p>\n

1 ev = 1,6.10<\/b><\/span><\/span><\/span>-19<\/b><\/span><\/span><\/sup><\/span>\u00a0J\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0W = 7,92.10<\/b><\/span><\/span><\/span>-19x\"\"<\/b><\/span><\/span><\/sup><\/span>\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>W = 4,95 eV.<\/b><\/span><\/span><\/span><\/p>\n

B) Consultando<\/b><\/span><\/span><\/span>\u00a0a\u00a0<\/b><\/span><\/span><\/span>tabela\u00a0<\/b><\/span><\/span><\/span>voc\u00ea verifica que\u00a0<\/b><\/span><\/span><\/span>no<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>tempo m\u00e1ximo de exposi\u00e7\u00e3o \u2206t = 6,00 s o n\u00edvel de irradia\u00e7\u00e3o vale Ief\u00a0= 4,95.10<\/b><\/span><\/span><\/span>-4<\/b><\/span><\/span><\/sup><\/span>\u00a0Wcm<\/b><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Como, pelo\u00a0<\/b><\/span><\/span><\/span>enunciado a irradia\u00e7\u00e3o (Ief) \u00e9 definida como pot\u00eancia (P) incidente por unidade de \u00e1rea (S)\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Ief\u00a0=\u00a0\"\"\u00a0=\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0\"\"\u00a0Ief\u00a0=\u00a0\"\"\u00a0\"\"\u00a0W = I<\/b><\/span><\/span><\/span>ef<\/b><\/span><\/span><\/sub><\/span>.S.\u2206t = 4,95.10<\/b><\/span><\/span><\/span>-4<\/b><\/span><\/span><\/sup><\/span>.1.6\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0W\u00a0<\/b><\/span><\/span><\/span>= 29,7.10<\/b><\/span><\/span><\/span>-4<\/b><\/span><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>= 2,97.10<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>\u00a0J (energia<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>total <\/b><\/span><\/span><\/span>absorvida em\u00a0<\/b><\/span><\/span><\/span>cada 1 cm<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0de \u00e1rea de pele em \u2206t = 6,00 s).<\/b><\/span><\/span><\/span><\/p>\n

Como \u00e9\u00a0<\/b><\/span><\/span><\/span>pedido o n\u00famero n de f\u00f3tons,\u00a0<\/b><\/span><\/span><\/span>cada um\u00a0<\/b><\/span><\/span><\/span>com energia W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0= 7,92.10<\/b><\/span><\/span><\/span>-19<\/b><\/span><\/span><\/sup><\/span>\u00a0J,\u00a0<\/b><\/span><\/span><\/span>voc\u00ea ter\u00e1\u00a0<\/b><\/span><\/span><\/span>n =\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>=\u00a0\"\"\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>n = 3,75.10<\/b><\/span><\/span><\/span>15<\/b><\/span><\/span><\/sup><\/span>\u00a0f\u00f3tons.<\/b><\/span><\/span><\/span><\/p>\n

C)\u00a0<\/b><\/span><\/span><\/span>Utilizando\u00a0<\/b><\/span><\/span><\/span>a mesma equa\u00e7\u00e3o de (B), mas agora com a nova \u00e1rea S = 2 m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0= 2.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span>\u00a0cm<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>W = I<\/b><\/span><\/span><\/span>ef<\/b><\/span><\/span><\/sub><\/span>.S.\u2206t\u00a0<\/b><\/span><\/span><\/span>= 4,95.10<\/b><\/span><\/span><\/span>-4<\/b><\/span><\/span><\/sup><\/span>.2.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span>.6\u00a0\"\"\u00a0<\/b><\/span><\/span><\/span>W = 59,4 J<\/b><\/span><\/span><\/span><\/p>\n

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

\"\"<\/p>\n

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

 <\/p>\n

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

01\u00a0\"\"\u00a0Verdadeiro\u00a0\"\"\u00a0Einstein teorizou que as\u00a0<\/b><\/span><\/span>ondas eletromagn\u00e9ticas <\/b><\/span><\/span>(modelo ondulat\u00f3rio) s\u00f3 fariam com que os el\u00e9trons fossem ejetados <\/b><\/span><\/span>instantaneamente<\/b><\/span><\/span>\u00a0se elas se comportassem como\u00a0<\/b><\/span><\/span>part\u00edculas<\/b><\/span><\/span>\u00a0(modelo corpuscular).<\/b><\/span><\/span><\/span><\/span><\/p>\n

02\u00a0\"\"\u00a0Falso\u00a0\"\"\u00a0A\u00a0<\/b><\/span><\/span>pot\u00eancia<\/b><\/span><\/span>\u00a0altera sim a quantidade de\u00a0<\/b><\/span><\/span>el\u00e9trons arrancados<\/b><\/span><\/span>, quanto\u00a0<\/b><\/span><\/span>maior<\/b><\/span><\/span>\u00a0a pot\u00eancia,\u00a0<\/b><\/span><\/span>maior<\/b><\/span><\/span>\u00a0o n\u00famero de el\u00e9trons ejetados. No caso o que altera a\u00a0<\/b><\/span><\/span>energia cin\u00e9tica\u00a0<\/b><\/span><\/span>\u00e9 a\u00a0<\/b><\/span><\/span>frequ\u00eancia<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

04\u00a0\"\"\u00a0Verdadeiro\u00a0\"\"\u00a0De acordo com o primeiro postulado da teoria da relatividade (princ\u00edpio da relatividade), as leis que governam as mudan\u00e7as de estado em\u00a0<\/b><\/span><\/span>quaisquer<\/b><\/span><\/span>\u00a0sistemas f\u00edsicos tomam a\u00a0<\/b><\/span><\/span>mesma forma\u00a0<\/b><\/span><\/span>em <\/b><\/span><\/span>quaisquer<\/b><\/span><\/span>\u00a0sistemas de\u00a0<\/b><\/span><\/span>coordenadas inerciais<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

08\u00a0\"\"\u00a0Verdadeiro\u00a0\"\"\u00a0De acordo com o segundo postulado da teoria da relatividade (invari\u00e2ncia da velocidade da luz), a luz tem velocidade <\/b><\/span><\/span>invariante<\/b><\/span><\/span>\u00a0igual a c em rela\u00e7\u00e3o a\u00a0<\/b><\/span><\/span>qualquer<\/b><\/span><\/span>\u00a0sistema de coordenadas inercial.<\/b><\/span><\/span><\/span><\/span><\/p>\n

08-<\/b><\/span><\/span><\/span> \u03bb = h\/mv<\/b><\/span><\/span>\u00a0\u2014\u00a0<\/b><\/span><\/span>\u03bb = 6,63.10<\/b><\/span><\/span>-34<\/b><\/span><\/sup><\/span>\/9,14.10<\/b><\/span><\/span>-31<\/b><\/span><\/sup><\/span>.7,28.10<\/b><\/span><\/span>6<\/b><\/span><\/sup><\/span>\u00a0= 6,63.10<\/b><\/span><\/span>-34<\/b><\/span><\/sup><\/span>\/66,54.10<\/b><\/span><\/span>-25<\/b><\/span><\/sup><\/span>\u2014 \u03bb = 0,1.10<\/b><\/span><\/span>-9<\/b><\/span><\/sup><\/span>\u00a0\u2014\u00a0<\/b><\/span><\/span>\u03bb = 10<\/b><\/span><\/span>-10<\/b><\/span><\/sup><\/span>\u00a0m<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

 <\/p>\n

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

\u00a0<\/span>1.<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Esse efeito foi observado\u00a0<\/b><\/span><\/span><\/span>primeiramente por Henrich Hertz<\/b><\/span><\/span><\/span>\u00a0e sua explica\u00e7\u00e3o\u00a0<\/b><\/span><\/span><\/span>correta foi publicada em 1905 por Niels Bohr.<\/b><\/span><\/span><\/span><\/p>\n

1.<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Falsa<\/b><\/span><\/span><\/span>\u00a0\u2014\u00a0<\/b><\/span><\/span><\/span>Esse efeito foi observado\u00a0<\/b><\/span><\/span><\/span>primeiramente por Henrich Hertz,<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>mas<\/b><\/span><\/span><\/span>\u00a0sua explica\u00e7\u00e3o correta foi publicada<\/b><\/span><\/span><\/span>\u00a0em 1905 por Albert Einstein.<\/b><\/span><\/span><\/span><\/p>\n

2.<\/b><\/span><\/span><\/span>\u00a0A\u00a0<\/b><\/span><\/span><\/span>explica\u00e7\u00e3o correta desse efeito utilizou uma\u00a0<\/b><\/span><\/span><\/span>ideia de Max Planck<\/b><\/span><\/span><\/span>, de que a luz incidente n\u00e3o poderia ter energia com um valor qualquer, mas sim\u00a0<\/b><\/span><\/span><\/span>uma energia dada por m\u00faltiplos inteiros de uma por\u00e7\u00e3o elementar.<\/b><\/span><\/span><\/span><\/p>\n

2.\u00a0<\/b><\/span><\/span><\/span>Correta<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u2014\u00a0<\/b><\/span><\/span><\/span>Planck<\/b><\/span><\/span><\/span><\/span>\u00a0definiu que a radia\u00e7\u00e3o era emitida e absorvida em pacotes de<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>energia,<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>bem definidos e em quantidades discretas<\/b><\/span><\/span><\/span>. <\/b><\/span><\/span><\/span><\/p>\n

Denominou esta\u00a0<\/b><\/span><\/span><\/span>quantidade de<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>energia de\u00a0quantum<\/b><\/span><\/span><\/span>\u00a0(plural =\u00a0quanta) e afirmou que cada part\u00edcula \u201clocalizava-se\u201d em n\u00edveis de\u00a0<\/b><\/span><\/span><\/span>energia quantizados<\/b><\/i><\/span><\/span><\/span>\u00a0ou\u00a0<\/b><\/span><\/span><\/span>estados qu\u00e2nticos<\/b><\/i><\/span><\/span><\/span>, marcando com isso, o nascimento\u00a0da teoria qu\u00e2ntica.<\/b><\/span><\/span><\/span><\/p>\n

3.<\/b><\/span><\/span><\/span>\u00a0Segundo o\u00a0<\/b><\/span><\/span><\/span>modelo proposto, cada f\u00f3ton,<\/b><\/span><\/span><\/span>\u00a0ao colidir com um el\u00e9tron,\u00a0<\/b><\/span><\/span><\/span>transfere-lhe<\/b><\/span><\/span><\/span>\u00a0uma quantidade de energia proporcional a sua\u00a0<\/b><\/span><\/span><\/span>velocidade.<\/b><\/span><\/span><\/span><\/p>\n

3.<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Falsa\u00a0<\/b><\/span><\/span><\/span>\u2014 O\u00a0<\/b><\/span><\/span><\/span>efeito fotoel\u00e9trico\u00a0ocorre\u00a0<\/b><\/span><\/span><\/span>quando uma placa met\u00e1lica \u00e9 exposta a uma\u00a0<\/b><\/span><\/span><\/span>radia\u00e7\u00e3o eletromagn\u00e9tica<\/b><\/span><\/span><\/span><\/a>\u00a0de\u00a0<\/b><\/span><\/span><\/span>frequ\u00eancia\u00a0<\/b><\/span><\/span><\/span>alta, por exemplo, um feixe de luz, e este arranca el\u00e9trons da placa met\u00e1lica.\u00a0<\/b><\/span><\/span><\/span>\u00c9 frequ\u00eancia e n\u00e3o velocidade.<\/b><\/span><\/span><\/span><\/p>\n

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

 <\/p>\n

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

02- Correta<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>\u2014\u00a0<\/b><\/span><\/span>As ondas s\u00e3o fortemente difratadas\u00a0 quando o\u00a0<\/b><\/span><\/span>comprimento de onda<\/b><\/span><\/span>\u00a0\u00a0tem\u00a0<\/b><\/span><\/span>aproximadamente o mesmo tamanho\u00a0 da abertura \u00a0da fenda<\/b><\/span><\/span>\u00a0(figura 2)\u00a0<\/b><\/span><\/span>ou do tamanho do obst\u00e1culo<\/b><\/span><\/span>\u00a0(figura 1).<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Figura 1\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

figura\u00a0 2<\/b><\/span><\/span><\/span><\/span><\/p>\n

Observe na figura da esquerda que a difra\u00e7\u00e3o \u00e9 menos acentuada que na direita.<\/b><\/span><\/span><\/span><\/span><\/p>\n

04. Correta<\/b><\/span><\/span>. \u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

08. Falsa<\/b><\/span><\/span>\u00a0\u2014\u00a0<\/b><\/span><\/span>\u03bb=h\/mV<\/b><\/span><\/span>=6,63.10-34\/9,1.10-31.3.106=6,63.10-34\/27,3.10-25\u00a0\u2014\u00a0<\/b><\/span><\/span>\u03bb=2,4.10-10m.<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

32. Falsa<\/b><\/span><\/span>\u00a0\u2014\u00a0Foi\u00a0<\/b><\/span><\/span>Thomas Young<\/b><\/span><\/span>\u00a0quem realizou o experimento da dupla fenda.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Soma (01 + 02 + 04)=07<\/b><\/span><\/span><\/span><\/span><\/p>\n


\n<\/b><\/span><\/span>11- <\/b><\/span><\/span><\/span>Veja um <\/b><\/span><\/span>resumo da teoria abaixo:<\/b><\/span><\/span><\/span><\/span><\/p>\n

Dilata\u00e7\u00e3o do tempo<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

12-<\/b><\/span><\/span><\/span> <\/b>O fato de se\u00a0<\/b><\/span><\/span>ter um ou mais cron\u00f4metros n\u00e3o influencia na medida do tempo<\/b><\/span><\/span>, por\u00e9m o\u00a0<\/b><\/span><\/span>tempo pr\u00f3prio,<\/b><\/span><\/span>\u00a0que \u00e9 nada mais que o tempo da pessoa que est\u00e1 em movimento em rela\u00e7\u00e3o a uma outra que est\u00e1 parada,\u00a0<\/b><\/span><\/span>sempre \u00e9 menor que o tempo da pessoa em repouso<\/b><\/span><\/span>, observe a figura a seguir:<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Sendo assim,\u00a0<\/b><\/span><\/span>como n\u00e3o h\u00e1 velocidade maior que a da luz, o tempo pr\u00f3prio s\u00f3 pode ser menor, alternativa A incorreta.<\/b><\/span><\/span>\u00a0Pelo mesmo racioc\u00ednio da A\u00a0<\/b><\/span><\/span>o rel\u00f3gio se encontra atrasado, alternativa B incorreta.<\/b><\/span><\/span>\u00a0As\u00a0<\/b><\/span><\/span>leis da f\u00edsica s\u00e3o invariantes para referencias que est\u00e3o em mesmas velocidades,\u00a0<\/b><\/span><\/span>sendo assim\u00a0<\/b><\/span><\/span>a alternativa C \u00e9 falsa. A alternativa D est\u00e1 correta<\/b><\/span><\/span>, pois realmente <\/b><\/span><\/span>o fato da luz ser constante e os referencias mudarem s\u00e3o respons\u00e1veis pela dilata\u00e7\u00e3o do tempo.<\/b><\/span><\/span>\u00a0E\u00a0<\/b><\/span><\/span>a alternativa E \u00e9 incorreta justamente pelo fato da velocidade da luz ser constante, n\u00e3o dependendo de referencial.<\/b><\/span><\/span><\/span><\/span><\/p>\n

13-<\/b><\/span><\/span><\/span> 01\u00a0\"\"\u00a0Verdadeiro\u00a0\"\"\u00a0Einstein teorizou que as\u00a0<\/b><\/span><\/span>ondas eletromagn\u00e9ticas<\/b><\/span><\/span>(modelo ondulat\u00f3rio) s\u00f3 fariam com que os el\u00e9trons fossem ejetados <\/b><\/span><\/span>instantaneamente<\/b><\/span><\/span>\u00a0se elas se comportassem como\u00a0<\/b><\/span><\/span>part\u00edculas<\/b><\/span><\/span>\u00a0(modelo corpuscular).<\/b><\/span><\/span><\/span><\/span><\/p>\n

02\u00a0\"\"\u00a0Falso\u00a0\"\"\u00a0A\u00a0<\/b><\/span><\/span>pot\u00eancia<\/b><\/span><\/span>\u00a0altera sim a quantidade de\u00a0<\/b><\/span><\/span>el\u00e9trons arrancados<\/b><\/span><\/span>, quanto\u00a0<\/b><\/span><\/span>maior<\/b><\/span><\/span>\u00a0a pot\u00eancia,\u00a0<\/b><\/span><\/span>maior<\/b><\/span><\/span>\u00a0o n\u00famero de el\u00e9trons ejetados. No caso o que altera a\u00a0<\/b><\/span><\/span>energia cin\u00e9tica\u00a0<\/b><\/span><\/span>\u00e9 a\u00a0<\/b><\/span><\/span>frequ\u00eancia<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

04\u00a0\"\"\u00a0Verdadeiro\u00a0\"\"\u00a0De acordo com o primeiro postulado da teoria da relatividade (princ\u00edpio da relatividade), as leis que governam as mudan\u00e7as de estado em\u00a0<\/b><\/span><\/span>quaisquer<\/b><\/span><\/span>\u00a0sistemas f\u00edsicos tomam a\u00a0<\/b><\/span><\/span>mesma forma\u00a0<\/b><\/span><\/span>em <\/b><\/span><\/span>quaisquer<\/b><\/span><\/span>\u00a0sistemas de\u00a0<\/b><\/span><\/span>coordenadas inerciais<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

08\u00a0\"\"\u00a0Verdadeiro\u00a0\"\"\u00a0De acordo com o segundo postulado da teoria da relatividade (invari\u00e2ncia da velocidade da luz), a luz tem velocidade <\/b><\/span><\/span>invariante<\/b><\/span><\/span>\u00a0igual a c em rela\u00e7\u00e3o a\u00a0<\/b><\/span><\/span>qualquer<\/b><\/span><\/span>\u00a0sistema de coordenadas inercial.<\/b><\/span><\/span><\/span><\/span><\/p>\n

14-<\/b><\/span><\/span><\/span> <\/b>I. Verdadeira<\/b><\/span><\/span>, a massa \u00e9 a medida da\u00a0<\/b><\/span><\/span>in\u00e9rcia<\/b><\/span><\/span>\u00a0de um corpo. Assim, \u00e0 medida que a\u00a0<\/b><\/span><\/span>velocidade de um corpo aumenta sua in\u00e9rcia tamb\u00e9m aumenta e quando a velocidade do corpo tende \u00e0 velocidade da<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>luz ( a maior poss\u00edvel), sua in\u00e9rcia\u00a0 e consequentemente sua massa tende ao infinito.<\/b><\/span><\/span>\u00a0Portanto, al\u00e9m do espa\u00e7o e do tempo, na teoria da velocidade a massa tamb\u00e9m varia e essa varia\u00e7\u00e3o \u00e9 fornecida pela express\u00e3o:<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Na express\u00e3o acima\u00a0m<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\u00a0\u00e9 denominada massa de repouso\u00a0e\u00a0m, de massa relativ\u00edstica.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Observe na express\u00e3o acima que, se a velocidade V do corpo tende \u00e0 velocidade da luz c\u00a0 \u2014\u00a0 m=m<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\/\u221a1 \u2013 V<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\/c<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0 \u2014\u00a0 m=m<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\/\u221a1 \u2013 c<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\/c<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0 \u2014\u00a0 m=m<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\/\u221a1 \u2013 1\u00a0 \u2014\u00a0 m=m<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>\/\"\"0\u00a0 \u2014\u00a0\u00a0<\/b><\/span><\/span>quando o denominador tende a zero, a massa m tende ao infinito.<\/b><\/span><\/span><\/span><\/span><\/p>\n

II. Falsa,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>a velocidade da luz\u00a0<\/b><\/span><\/span>n\u00e3o depende nem da velocidade do emissor<\/b><\/span><\/span>(fonte emissora da luz),\u00a0<\/b><\/span><\/span>nem da velocidade do receptor<\/b><\/span><\/span>\u00a0(observador) do sinal luminoso. A velocidade da luz no v\u00e1cuo \u00e9 a velocidade m\u00e1xima poss\u00edvel de transmiss\u00e3o de intera\u00e7\u00e3o na Natureza e seu valor \u00e9 c=3,0.10<\/b><\/span><\/span>8<\/b><\/span><\/sup><\/span>m\/s. Ela\u00a0<\/b><\/span><\/span>n\u00e3o depende do sistema de refer\u00eancia inercial adotado.<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

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

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

Vestibulares Recentes \u2013 Resolu\u00e7\u00e3o Comentada F\u00cdSICA MODERNA \u2013 2017 \u2013 2016 \u2013 2015 01- \u00a0a. Falsa\u00a0\u00a0O\u00a0efeito fotoel\u00e9trico ocorre quando\u00a0a luz\u00a0(onda eletromagn\u00e9tica, radia\u00e7\u00e3o eletromagn\u00e9tica)\u00a0de frequ\u00eancia suficientemente alta incide sobre a superf\u00edcie de um metal, ela pode retirar el\u00e9trons do mesmo. b. Falsa\u00a0\u00a0Nas l\u00e2mpadas\u00a0incandescentes a emiss\u00e3o de luz ocorre devido ao aquecimento de seu filamento\u00a0por\u00a0efeito Joule\u00a0(choque dos el\u00e9trons da corrente el\u00e9trica com<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3388,"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-3390","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3390","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=3390"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3390\/revisions"}],"predecessor-version":[{"id":3393,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3390\/revisions\/3393"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3388"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3390"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}