{"id":1519,"date":"2015-11-16T15:11:57","date_gmt":"2015-11-16T15:11:57","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=1519"},"modified":"2024-09-03T13:38:25","modified_gmt":"2024-09-03T13:38:25","slug":"afa-2015-2016-resolucao","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2016\/afa-20152016\/afa-2015-2016-resolucao\/","title":{"rendered":"AFA 2015\/2016 – Resolu\u00e7\u00e3o"},"content":{"rendered":"

Resolu\u00e7\u00e3o comentada das quest\u00f5es para a admiss\u00e3o da<\/span><\/span><\/span><\/p>\n

AFA 2015\/2016<\/span><\/span><\/span><\/p>\n

01- <\/span><\/span><\/span>Em todo <\/b><\/span><\/span><\/span>gr\u00e1fico VXt<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>\u00e1rea<\/b><\/span><\/span><\/span> entre a <\/b><\/span><\/span><\/span>reta representativa e o eixo dos tempos<\/b><\/span><\/span><\/span> <\/b>\u00e9 numericamente<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

igual \u00e0<\/b><\/span><\/span><\/span> varia\u00e7\u00e3o de espa\u00e7o \u0394S<\/b><\/span><\/span><\/span>, entre dois instantes quaisquer <\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0e t<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Os corpos A e B voltam a se encontrar quando as <\/b><\/span><\/span><\/span>\u00e1reas entre as curvas caracter\u00edsticas da velocidade<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

(v) e o tempo (t) <\/b><\/span><\/span><\/span>forem iguais. Analisando o gr\u00e1fico as \u00e1reas s\u00e3o iguais no instante t<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

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

02- <\/span><\/span><\/span>Segunda lei de Newton ou Princ\u00edpio Fundamental da Din\u00e2mica<\/b><\/span><\/span><\/span><\/p>\n

Ao contr\u00e1rio da <\/b><\/span><\/span><\/span>primeira lei<\/b><\/span><\/span><\/span> igual \u00e0<\/b><\/span><\/span><\/span> de Newton<\/b><\/span><\/span><\/span> que justifica o que ocorre com um corpo quando a <\/b><\/span><\/span><\/span>for\u00e7a resultante que<\/b><\/span><\/span><\/span> <\/b>age sobre ele for nula<\/b><\/span><\/span><\/span>, esta <\/b><\/span><\/span><\/span>segunda lei de Newton<\/b><\/span><\/span><\/span> explica o que acontece com esse corpo quando a <\/b><\/span><\/span><\/span>resultante das for\u00e7as que agem sobre ele n\u00e3o for nula.<\/b><\/span><\/span><\/span><\/p>\n

Podemos definir o <\/b><\/span><\/span><\/span>Princ\u00edpio Fundamental da Din\u00e2mica<\/b><\/span><\/span><\/span> ou <\/b><\/span><\/span><\/span>segunda lei de Newton do seguinte<\/b><\/span><\/span><\/span> modo:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

03- <\/span><\/span><\/span>Dilata\u00e7\u00e3o linear dos s\u00f3lidos<\/b><\/span><\/span><\/span><\/p>\n

\u00a0Trata-se da dilata\u00e7\u00e3o de uma das dimens\u00f5es de um corpo, como por exemplo, seu comprimento. <\/b><\/span><\/span><\/span>Considere uma <\/b><\/span><\/span><\/span>haste met\u00e1lica de comprimento L<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span> e \u00e0 <\/b><\/span><\/span><\/span>temperatura t<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span> Quando <\/b><\/span><\/span><\/span>aquecida<\/b><\/span><\/span><\/span> ter\u00e1 <\/b><\/span><\/span><\/span>comprimento L a uma temperatura t.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"\u00a0Caracter\u00edsticas:<\/b><\/span><\/span><\/span><\/p>\n

A dilata\u00e7\u00e3o linear \u0394L \u00e9 diretamente proporcional \u00e0 varia\u00e7\u00e3o de temperatura \u0394t<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/p>\n

A dilata\u00e7\u00e3o linear \u0394L \u00e9 diretamente proporcional ao comprimento inicial L<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

A dilata\u00e7\u00e3o linear \u0394L depende do material de que \u00e9 constitu\u00eddo o corpo.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u0394L\u00a0\"\"\u00a0 dilata\u00e7\u00e3o linear<\/b><\/span><\/span><\/span><\/p>\n

\u03b1\u00a0 \"\" coeficiente de dilata\u00e7\u00e3o linear m\u00e9dio, caracter\u00edstica do material que constitui a barra.<\/b><\/span><\/span><\/span><\/p>\n

L<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>\u00a0 \"\" comprimento inicial<\/b><\/span><\/span><\/span><\/p>\n

L\u00a0 \"\" comprimento final<\/b><\/span><\/span><\/span><\/p>\n

\u0394t\u00a0 \"\"\u00a0 intervalo de temperatura<\/b><\/span><\/span><\/span><\/p>\n

Analisando as alternativas<\/b><\/span><\/span><\/span>:<\/b><\/span><\/span><\/p>\n

a)<\/b><\/span><\/span><\/span> num dia de ver\u00e3o em que a <\/b><\/span><\/span><\/span>temperatura variar 20 \u00b0C<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>comprimento de uma barra de ferro de 10,0 m sofrer\u00e1 uma varia\u00e7\u00e3o de 2,6 cm<\/b><\/span><\/span><\/span><\/p>\n

a – Falsa<\/b><\/span><\/span><\/span><\/p>\n

\u0394L = L<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>.\u03b1. \u0394t\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\u0394L = 10.13.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span>.20<\/b><\/span><\/span><\/span><\/p>\n

\u0394L = 26. 10<\/b><\/span><\/span><\/span>-4 <\/b><\/span><\/span><\/sup><\/span>m = 0,26 cm<\/b><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>coeficiente de dilata\u00e7\u00e3o superficial do ferro \u00e9 169.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span> <\/b>o<\/b><\/span><\/span><\/sup><\/span>C<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

b – Falsa<\/b><\/span><\/span><\/span><\/p>\n

\uf062<\/span> = 2.\u03b1 \"\" <\/b><\/span><\/span><\/span>\uf062<\/b><\/span><\/span><\/span> = 2. 13.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span> \u00baC<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span> \"\" <\/b><\/span><\/span><\/span>\uf062<\/b><\/span><\/span><\/span> = 26.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span> \u00baC<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span><\/p>\n

c)<\/b><\/span><\/span><\/span> para <\/b><\/span><\/span><\/span>cada 1 \u00b0C de varia\u00e7\u00e3o de temperatura<\/b><\/span><\/span><\/span>, o <\/b><\/span><\/span><\/span>comprimento de uma barra de 1,0 m desse material varia 13.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span>m\u22c5<\/b><\/span><\/span><\/span><\/p>\n

c – Verdadeira<\/b><\/span><\/span><\/span><\/p>\n

\u0394L = L<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>.\u03b1. \u0394t\u00a0\"\" \u0394L = 1.13.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span>.1 \"\" <\/b><\/span><\/span><\/span><\/b>\u0394L = 13.10<\/b><\/span><\/span><\/span>-6 <\/b><\/span><\/span><\/sup><\/span>m<\/b><\/span><\/span><\/span><\/p>\n

d)<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>coeficiente de dilata\u00e7\u00e3o volum\u00e9trica do ferro \u00e9 39.10<\/b><\/span><\/span><\/span>-18<\/b><\/span><\/span><\/sup><\/span> <\/b>o<\/b><\/span><\/span><\/sup><\/span>C<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span><\/p>\n

d – Falsa<\/b><\/span><\/span><\/span><\/p>\n

\uf067<\/span> = 3.\u03b1 \"\" <\/b><\/span><\/span><\/span>\uf067<\/b><\/span><\/span><\/span> = 3.13.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span> \"\" <\/b><\/span><\/span><\/span>\uf067<\/b><\/span><\/span><\/span> = 39.10<\/b><\/span><\/span><\/span>-6<\/b><\/span><\/span><\/sup><\/span> <\/b>\u00baC<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span><\/p>\n

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

04- <\/span><\/span><\/span>1\u00ba passo:<\/b><\/span><\/span><\/span><\/p>\n

Determinar a massa \"\" d = m\/V \"\" 1kg\/L = m.1L \"\" m = 1 kg = 1000 g.<\/b><\/span><\/span><\/span><\/p>\n

Agora calculamos<\/b><\/span><\/span><\/span> a quantidade de calor utilizada na queima, <\/b><\/span><\/span><\/span>usando a equa\u00e7\u00e3o fundamental da calorimetria.<\/b><\/span><\/span><\/span><\/p>\n

Equa\u00e7\u00e3o fundamental da calorimetria – calor sens\u00edvel ou calor espec\u00edfico.<\/b><\/span><\/span><\/span><\/p>\n

Denomina-se <\/b><\/span><\/span><\/span>calor sens\u00edvel ou calor espec\u00edfico (c) <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>calor <\/b><\/span><\/span><\/span>que provoca uma <\/b><\/span><\/span><\/span>varia\u00e7\u00e3o na temperatura de um corpo, sem que ele mude de estado f\u00edsico.<\/b><\/span><\/span><\/span><\/p>\n

Verifica-se experimentalmente que a <\/b><\/span><\/span><\/span>quantidade de calor (Q) recebida ou cedida por um corpo \u00e9 diretamente proporcional \u00e0 sua massa e \u00e1 sua varia\u00e7\u00e3o de temperatura<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Matematicamente:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Onde <\/b><\/span><\/span><\/span>c \u00e9 o calor especifico<\/b><\/span><\/span><\/span> (constante de proporcionalidade que \u00e9 caracter\u00edstica de cada corpo).<\/b><\/span><\/span><\/span><\/p>\n

Q = m.c.<\/b><\/span><\/span><\/span> \u0394t\u00a0 \"\" Q = 1000.1.(100-10) \"\" <\/b><\/span><\/span><\/span>Q = 90000 cal.<\/b><\/span><\/span><\/span><\/p>\n

Se 80% do carv\u00e3o liberado \u00e9 perdido, <\/b><\/span><\/span><\/span>aproveita-se apenas 20%, <\/b><\/span><\/span><\/span>logo:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

E, finalmente,<\/b><\/span><\/span><\/span> determinamos a pot\u00eancia t\u00e9rmica, sendo dado 1cal = 4J \"\" W = Q = 450000×4 = 1800000 J em \u2206t = 10min = 10.60 = 600 s:<\/b><\/span><\/span><\/span><\/p>\n

P <\/b><\/span><\/span><\/span>= W \/\u2206t = 1800000\/600 <\/b><\/span><\/span><\/span>= 3000 W.<\/b><\/span><\/span><\/span><\/p>\n

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

05- <\/span><\/span><\/span>Caracter\u00edsticas da imagem num espelho plano<\/b><\/span><\/span><\/span><\/p>\n

\"\"\u00a0\u00a0<\/span>O ponto objeto e o ponto imagem s\u00e3o sim\u00e9tricos<\/b><\/span><\/span><\/span> <\/b>em rela\u00e7\u00e3o ao espelho<\/b><\/span><\/span><\/span>, ou seja, <\/b><\/span><\/span><\/span>a dist\u00e2ncia do objeto ao espelho \u00e9 a mesma que a dist\u00e2ncia da imagem ao espelho<\/b><\/span><\/span><\/span>e contidos numa mesma reta perpendicular ao plano do espelho.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"\u00a0O ponto imagem est\u00e1 sempre atr\u00e1s do espelho e \u00e9 virtual<\/b><\/span><\/span><\/span> <\/b>(n\u00e3o pode ser fotografado ou filmado atr\u00e1s do espelho).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"\u00a0<\/span>A altura do objeto \u00e9 sempre igual \u00e0 altura da imagem<\/b><\/span><\/span><\/span> <\/b>e a imagem \u00e9 reversa ou revertida (troca direita pela esquerda).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Logo, <\/b><\/span><\/span><\/span>a Imagem gerada por um espelho plano \u00e9 sempre virtual (formada atr\u00e1s do espelho), direita (mesma posi\u00e7\u00e3o do objeto original) e igual (mesmo tamanho do\u00a0 objeto original).<\/b><\/span><\/span><\/span> A imagem gerada por um espelho plano (EP) est\u00e1 situada a uma dist\u00e2ncia (p) do espelho igual \u00e0 dist\u00e2ncia (p\u2019) que o objeto (O) se encontra do espelho.<\/b><\/span><\/span><\/span><\/p>\n

Veja a vis\u00e3o dos objetos pelo Observador 1<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ou, de uma<\/b><\/span><\/span><\/span> maneira bem simples:<\/b><\/span><\/span><\/span><\/p>\n

Os objetos que est\u00e3o no lado do observador n\u00e3o mudam. Podemos observar isto apenas em B.<\/b><\/span><\/span><\/span><\/p>\n

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

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

\"\"<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

07- <\/span><\/span><\/span>Conseguimos obter a <\/b><\/span><\/span><\/span>quantidade de calor Q<\/b><\/span><\/span><\/span> fazendo uma <\/b><\/span><\/span><\/span>rela\u00e7\u00e3o<\/b><\/span><\/span><\/span> entre a <\/b><\/span><\/span><\/span>pot\u00eancia el\u00e9trica e a pot\u00eancia t\u00e9rmica:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>varia\u00e7\u00e3o de energia interna<\/b><\/span><\/span><\/span> <\/b>\u2206U<\/b><\/span><\/span><\/span> do g\u00e1s pode ser dada pela <\/b><\/span><\/span><\/span>1\u00aa lei da termodin\u00e2mica:<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/p>\n

O Primeiro Princ\u00edpio da Termodin\u00e2mica (Princ\u00edpio da Conserva\u00e7\u00e3o da Energia) afirma que:<\/b><\/span><\/span><\/span> <\/b>\u201cA energia n\u00e3o pode ser criada nem destru\u00edda, mas apenas transformada\u201d<\/b><\/span><\/span><\/span><\/p>\n

Suponha que um <\/b><\/span><\/span><\/span>sistema isolado receba 300J de calor.<\/b><\/span><\/span><\/span> Se, por exemplo, <\/b><\/span><\/span><\/span>50J dessa energia<\/b><\/span><\/span><\/span> forem <\/b><\/span><\/span><\/span>absorvidos <\/b><\/span><\/span><\/span>pelo sistema, ent\u00e3o a <\/b><\/span><\/span><\/span>parte restante, 250J, ser\u00e1 fornecida ao ambiente sob a forma de trabalho.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ent\u00e3o, Q = W + \u0394U ou,<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

08- <\/span><\/span><\/span>For\u00e7a magn\u00e9tica sobre um fio retil\u00edneo percorrido por corrente el\u00e9trica i<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

F<\/b><\/span><\/span><\/span>m<\/b><\/span><\/span><\/sub><\/span>\u00a0<\/b><\/span><\/span><\/span>\u2013 <\/b><\/span><\/span>intensidade da for\u00e7a magn\u00e9tica<\/b><\/span><\/span><\/span> <\/b>que age sobre o fio \u2013 medida em newton (N), no SI.<\/b><\/span><\/span><\/span><\/p>\n

B<\/b><\/span><\/span><\/span> \u2013 <\/b><\/span><\/span>intensidade do campo magn\u00e9tico<\/b><\/span><\/span><\/span> \u2013 <\/b><\/span><\/span>medido em tesla (T), no SI.<\/b><\/span><\/span><\/span><\/p>\n

i<\/b><\/span><\/span><\/span> \u2013 <\/b><\/span><\/span>corrente el\u00e9trica no fio<\/b><\/span><\/span><\/span> \u2013 <\/b><\/span><\/span>medida em amp\u00e8re (A), no SI.<\/b><\/span><\/span><\/span><\/p>\n

\u03b8 <\/b><\/span><\/span><\/span>\u2013 <\/b><\/span><\/span>\u00e2ngulo entre a dire\u00e7\u00e3o de B e de i.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span>for\u00e7a magn\u00e9tica nos fios<\/b><\/span><\/span><\/span> <\/b>n\u00e3o provoca<\/b><\/span><\/span><\/span> <\/b>torque resultante<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span>ou seja, a<\/b><\/span><\/span><\/span> <\/b>espira n\u00e3o consegue girar,<\/b><\/span><\/span><\/span> <\/b>pois o <\/b><\/span><\/span><\/span>suporte S impede esse giro<\/b><\/span><\/span><\/span> que seria no sentido anti-hor\u00e1rio.<\/b><\/span><\/span><\/span><\/p>\n

Assim, <\/b><\/span><\/span><\/span>a espira<\/b><\/span><\/span><\/span> <\/b>permanecer\u00e1 <\/b><\/span><\/span><\/span>na sua posi\u00e7\u00e3o original de equil\u00edbrio.<\/b><\/span><\/span><\/span><\/p>\n

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

09- <\/span><\/span><\/span>P\u00eandulo Simples<\/b><\/span><\/span><\/span><\/span><\/p>\n

P\u00eandulo Simples<\/b><\/span><\/span>\u00a0\"\"<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>consta de uma<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>massa m<\/b><\/span><\/span>, presa na<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>extremidade inferior de um fio ideal,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>fixada verticalmente<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>na sua extremidade superior (figura)\u00a0.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Se o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>p\u00eandulo simples<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>oscilar, com oscila\u00e7\u00f5es de pequena abertura<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>(no m\u00e1ximo 15o)<\/b><\/span><\/span>, ele descreve um<\/b><\/span><\/span>movimento circular de raio R=L, sendo L o comprimento do fio.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Seu<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>per\u00edodo (T),<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>que \u00e9 o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>tempo que ele demora para efetuar um \u201cvai e vem\u201d completo<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>\u00e9<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>fornecido pela express\u00e3o:<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

onde<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>g \u00e9 a acelera\u00e7\u00e3o da gravidade local.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"\u00a0<\/span>A<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>massa pendular m n\u00e3o influi no per\u00edodo T do movimento<\/b><\/span><\/span>. Assim dois p\u00eandulos de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>mesmo<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

comprimento L<\/b><\/span><\/span>, mas de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>massas diferentes M e m, apresentam o mesmo per\u00edodo T.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"\u00a0<\/span>O<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>per\u00edodo de um p\u00eandulo simples<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>independe da amplitude<\/b><\/span><\/span>, ou seja,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>da altura em que m \u00e9 abandonada<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Assim, os<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>p\u00eandulos da figura abaixo, tanto na<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>situa\u00e7\u00e3o 1 como na 2,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>demoram o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>mesmo tempo para<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

ir de A at\u00e9 B, de B at\u00e9 C, de C at\u00e9 B e de B at\u00e9 A.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"\u00a0<\/span>O<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>per\u00edodo<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>T<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>de um p\u00eandulo simples \u00e9<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>diretamente proporcional \u00e0 raiz quadrada de seu<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>comprimento L.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"\u00a0<\/span>O<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>per\u00edodo de um p\u00eandulo simples \u00e9 inversamente proporcional \u00e0 raiz quadrada da acelera\u00e7\u00e3o da gravidade g. A<\/b><\/span><\/span>ssim,\u00a0<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>quanto<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>maior for a acelera\u00e7\u00e3o da gravidade g do local<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>onde est\u00e1 o p\u00eandulo,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>menor ser\u00e1 o seu per\u00edodo.<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>Uma das<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>aplica\u00e7\u00f5e<\/b><\/span><\/span>s do p\u00eandulo simples \u00e9 a<\/b><\/span><\/span>determina\u00e7\u00e3o da acelera\u00e7\u00e3o da<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>gravidade em um dado local.<\/b><\/span><\/span><\/span><\/span><\/p>\n

No caso do exerc\u00edcio, vamos <\/b><\/span><\/span><\/span>C\u00e1lcular o <\/b><\/span><\/span><\/span>Per\u00edodo T<\/b><\/span><\/span><\/span> (tempo que demora para efetuar uma oscila\u00e7\u00e3o completa, um \u201cvai e vem\u201d completo), ou seja, <\/b><\/span><\/span><\/span>percorrer um comprimento de onda 1 \u03bb), utilizando os gr\u00e1ficos fornecidos:<\/b><\/span><\/span><\/span><\/b><\/p>\n

\"\"<\/p>\n

Observe que os <\/b><\/span><\/span><\/span>per\u00edodos dos p\u00eandulos 1, 2 e 3<\/b><\/span><\/span><\/span> s\u00e3o, respectivamente <\/b><\/span><\/span><\/span>T<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span> = 1s, T<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span> = 2s e T<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span> = 4s.<\/b><\/span><\/span><\/span><\/p>\n

Equa\u00e7\u00e3o do <\/b><\/span><\/span><\/span>per\u00edodo de um p\u00eandulo<\/b><\/span><\/span><\/span> <\/b>T = 2\u03c0\u221aL g<\/b><\/span><\/span><\/span> <\/b>substituindo g = \u03c0<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span> m\/s<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span> T = 2\u03c0\u221aL \u03c0<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span><\/b><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\"\" \"\"<\/span><\/p>\n

\"\"<\/p>\n

R- C<\/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 para a admiss\u00e3o da AFA 2015\/2016 01- Em todo gr\u00e1fico VXt a \u00e1rea entre a reta representativa e o eixo dos tempos \u00e9 numericamente igual \u00e0 varia\u00e7\u00e3o de espa\u00e7o \u0394S, entre dois instantes quaisquer t1\u00a0e t2. Os corpos A e B voltam a se encontrar quando as \u00e1reas entre as curvas caracter\u00edsticas da velocidade (v) e<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1517,"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-1519","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1519","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=1519"}],"version-history":[{"count":3,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1519\/revisions"}],"predecessor-version":[{"id":11010,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1519\/revisions\/11010"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1517"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=1519"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}