{"id":2899,"date":"2017-04-12T05:36:05","date_gmt":"2017-04-12T05:36:05","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=2899"},"modified":"2024-09-02T16:28:45","modified_gmt":"2024-09-02T16:28:45","slug":"ondulatoria","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/raciocinio-logico\/ondulatoria\/","title":{"rendered":"Ondulat\u00f3ria"},"content":{"rendered":"

Racioc\u00ednio L\u00f3gico<\/b><\/span><\/span><\/span><\/p>\n

Ondulat\u00f3ria<\/b><\/span><\/span><\/span><\/p>\n

Como esse conte\u00fado envolve muita teoria, em caso de d\u00favidas voc\u00ea pode <\/b><\/span><\/span><\/span>encontr\u00e1-la em<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>fisicaevestibular.com.br \u2013 Ondulat\u00f3ria<\/b><\/span><\/span><\/span><\/p>\n

01-(UEPA-PA)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Em uma\u00a0<\/b><\/span><\/span><\/span>brincadeira infantil\u00a0conhecida como\u00a0\u201ctelefone de barbante\u201d,\u00a0duas crian\u00e7as <\/b><\/span><\/span><\/span>prendem as<\/b><\/span><\/span><\/span><\/p>\n

extremidades de um barbante, <\/b><\/span><\/span><\/span>que \u00e9\u00a0<\/b><\/span><\/span><\/span>mantido esticado, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>fundo <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>dois copos <\/b><\/span><\/span><\/span>descart\u00e1veis,<\/b><\/span><\/span><\/span><\/p>\n

conforme mostrado na <\/b><\/span><\/span><\/span>figura abaixo.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>funcionamento <\/b><\/span><\/span><\/span>do brinquedo \u00e9 <\/b><\/span><\/span><\/span>baseado<\/b><\/span><\/span><\/span> no fato de que os\u00a0<\/b><\/span><\/span><\/span>sons produzidos <\/b><\/span><\/span><\/span>por <\/b><\/span><\/span><\/span>uma das crian\u00e7as <\/b><\/span><\/span><\/span>\u00e9<\/b><\/span><\/span><\/span><\/p>\n

coletado em um dos copos <\/b><\/span><\/span><\/span>e, em seguida, <\/b><\/span><\/span><\/span>transmitido ao outro copo por meio do fio, <\/b><\/span><\/span><\/span>na forma de\u00a0um\u00a0<\/b><\/span><\/span><\/span>pulso mec\u00e2nico. <\/b><\/span><\/span><\/span><\/p>\n

Admita que o fio de\u00a0<\/b><\/span><\/span><\/span>densidade volum\u00e9trica\u00a0<\/b><\/span><\/span><\/span>\u03c1<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>tenha um <\/b><\/span><\/span><\/span>comprimento igual a\u00a0<\/b><\/span><\/span><\/span>L<\/b><\/span><\/span><\/span>,\u00a0di\u00e2metro\u00a0<\/b><\/span><\/span><\/span>d<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e esteja <\/b><\/span><\/span><\/span>submetido<\/b><\/span><\/span><\/span> a uma\u00a0<\/b><\/span><\/span><\/span>for\u00e7a de tra\u00e7\u00e3o\u00a0<\/b><\/span><\/span><\/span>F<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Sob <\/b><\/span><\/span><\/span>essas condi\u00e7\u00f5es, <\/b><\/span><\/span><\/span>afirma-se que o <\/b><\/span><\/span><\/span>pulso transmitido pelo fio\u00a0propaga-se a uma velocidade dada por:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

02-(UFAM-AM)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Poucos sabem, mas\u00a0<\/b><\/span><\/span><\/span>Nathan Xavier de Albuquerque <\/b><\/span><\/span><\/span>(1922-2013),\u00a0que foi <\/b><\/span><\/span><\/span>empres\u00e1rio<\/b><\/span><\/span><\/span> e um dos <\/b><\/span><\/span><\/span>empreendedores mais importantes que o Estado do Amazonas <\/b><\/span><\/span><\/span>j\u00e1 teve, \u00e9 o <\/b><\/span><\/span><\/span>inventor do\u00a0motor rabeta,<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

muito <\/b><\/span><\/span><\/span>popular entre os ribeirinhos <\/b><\/span><\/span><\/span>por ser bem <\/b><\/span><\/span><\/span>mais barato que o motor de popa, <\/b><\/span><\/span><\/span>consumir <\/b><\/span><\/span><\/span>pouqu\u00edssimo combust\u00edvel <\/b><\/span><\/span><\/span>e poder ser <\/b><\/span><\/span><\/span>usado em qualquer filete de \u00e1gua. <\/b><\/span><\/span><\/span><\/p>\n

Considere a <\/b><\/span><\/span><\/span>seguinte situa\u00e7\u00e3o:\u00a0<\/b><\/span><\/span><\/span>uma <\/b><\/span><\/span><\/span>canoa<\/b><\/span><\/span><\/span>, equipada com <\/b><\/span><\/span><\/span>motor rabeta, <\/b><\/span><\/span><\/span>se <\/b><\/span><\/span><\/span>movimenta <\/b><\/span><\/span><\/span>com a\u00a0<\/b><\/span><\/span><\/span>velocidade de 8<\/b><\/span><\/span><\/span>m\/s\u00a0<\/b><\/i><\/span><\/span><\/span>em sentido contr\u00e1rio ao da propaga\u00e7\u00e3o das ondas peri\u00f3dicas produzidas pelo vento nas \u00e1guas de um lago. <\/b><\/span><\/span><\/span><\/p>\n

Se a\u00a0<\/b><\/span><\/span><\/span>velocidade de propaga\u00e7\u00e3o das ondas \u00e9 de 2<\/b><\/span><\/span><\/span>m\/s<\/b><\/i><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>e a <\/b><\/span><\/span><\/span>dist\u00e2ncia entre duas cristas sucessivas <\/b><\/span><\/span><\/span>\u00e9 de <\/b><\/span><\/span><\/span>10<\/b><\/span><\/span><\/span>m<\/b><\/i><\/span><\/span><\/span>,<\/b><\/span><\/span><\/span>\u00a0podemos afirmar que o\u00a0<\/b><\/span><\/span><\/span>per\u00edodo de oscila\u00e7\u00e3o da canoa em movimento, devido \u00e0 passagem das ondas, \u00e9 de:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

03-(UPE-PE)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>p\u00eandulo \u00e9 solto a partir do\u00a0repouso, <\/b><\/span><\/span><\/span>e o seu <\/b><\/span><\/span><\/span>movimento subsequente <\/b><\/span><\/span><\/span>\u00e9 mostrado na <\/b><\/span><\/span><\/span>figura.<\/b><\/span><\/span><\/span><\/p>\n

Sabendo que ele\u00a0<\/b><\/span><\/span><\/span>gasta 2,0 s para percorrer a dist\u00e2ncia AC, <\/b><\/span><\/span><\/span>\u00e9\u00a0<\/b><\/span><\/span><\/span>CORRETO\u00a0afirmar <\/b><\/span><\/span><\/span>que <\/b><\/span><\/span><\/span>sua\u00a0amplitude e<\/b><\/span><\/span><\/span> <\/b>frequ\u00eancia\u00a0valem<\/b><\/span><\/span><\/span>, respectivamente,<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>AC e 0,12 Hz <\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>AB e 0,25 Hz <\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>BC e 1,0 Hz <\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>BA e 2,0 Hz <\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>BC e 4,0 Hz<\/b><\/span><\/span><\/span><\/p>\n

04-(CEDERJ-RJ)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>Figura 1<\/b><\/span><\/span><\/span> ilustra\u00a0<\/b><\/span><\/span><\/span>duas fotos tiradas <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>uma corda <\/b><\/span><\/span><\/span>na qual uma <\/b><\/span><\/span><\/span>onda se propaga para a direita.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

A <\/b><\/span><\/span><\/span>primeira foto, <\/b><\/span><\/span><\/span>representada pela\u00a0<\/b><\/span><\/span><\/span>curva cont\u00ednua, <\/b><\/span><\/span><\/span>foi tirada no <\/b><\/span><\/span><\/span>instante de tempo\u00a0t = 0\u00a0<\/b><\/span><\/span><\/span>e a\u00a0<\/b><\/span><\/span><\/span>segunda,<\/b><\/span><\/span><\/span> representada pela <\/b><\/span><\/span><\/span>curva tracejada, <\/b><\/span><\/span><\/span>foi tirada em um <\/b><\/span><\/span><\/span>instante de tempo posterior,\u00a0t = t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>. <\/b><\/span><\/span><\/span>A\u00a0<\/b><\/span><\/span><\/span>coordenada\u00a0vertical <\/b><\/span><\/span><\/span>descreve os\u00a0<\/b><\/span><\/span><\/span>deslocamentos dos pontos da c<\/b><\/span><\/span><\/span>orda em <\/b><\/span><\/span><\/span>rela\u00e7\u00e3o \u00e0s suas posi\u00e7\u00f5es <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>equil\u00edbrio,<\/b><\/span><\/span><\/span>\u00a0que <\/b><\/span><\/span><\/span>coincidem com o eixo horizontal com\u00a0coordenada x (em metros).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>Figura 2 <\/b><\/span><\/span><\/span>ilustra o <\/b><\/span><\/span><\/span>resultado de uma filmagem <\/b><\/span><\/span><\/span>e mostra o\u00a0<\/b><\/span><\/span><\/span>deslocamento vertical do ponto da corda <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>coordenada x = 0 em fun\u00e7\u00e3o do\u00a0tempo t (em segundos).<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>Determine o <\/b><\/span><\/span><\/span>valor\u00a0do comprimento da onda, especificando<\/b><\/span><\/span><\/span>\u00a0a figura <\/b><\/span><\/span><\/span>(1 ou 2)\u00a0<\/b><\/span><\/span><\/span>da qual a <\/b><\/span><\/span><\/span>informa\u00e7\u00e3o foi extra\u00edda.<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>Determine o <\/b><\/span><\/span><\/span>valor do\u00a0per\u00edodo da onda,<\/b><\/span><\/span><\/span>\u00a0especificando a\u00a0<\/b><\/span><\/span><\/span>figura (1 ou 2)\u00a0<\/b><\/span><\/span><\/span>da qual a <\/b><\/span><\/span><\/span>informa\u00e7\u00e3o foi extra\u00edda.<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>Encontre o\u00a0<\/b><\/span><\/span><\/span>valor m\u00ednimo de t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

05-(ENEM-MEC)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Em <\/b><\/span><\/span><\/span>viagens de avi\u00e3o, <\/b><\/span><\/span><\/span>\u00e9 solicitado aos passageiros o <\/b><\/span><\/span><\/span>desligamento de todos os aparelhos cujo<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

funcionamento <\/b><\/span><\/span><\/span>envolva a\u00a0emiss\u00e3o ou a recep\u00e7\u00e3o de<\/b><\/span><\/span><\/span> ondas eletromagn\u00e9ticas.<\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>procedimento \u00e9 utilizado <\/b><\/span><\/span><\/span>para <\/b><\/span><\/span><\/span>eliminar fontes de radia\u00e7\u00e3o que <\/b><\/span><\/span><\/span>possam\u00a0interferir\u00a0nas comunica\u00e7\u00f5es via r\u00e1dio dos pilotos com a torre de controle.<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>propriedade das ondas <\/b><\/span><\/span><\/span>emitidas que <\/b><\/span><\/span><\/span>justifica<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>procedimento adotado <\/b><\/span><\/span><\/span>\u00e9 o fato de<\/b><\/span><\/span><\/span><\/p>\n

A) <\/b><\/span><\/span><\/span>terem fases opostas. <\/b><\/span><\/span><\/span><\/p>\n

B) <\/b><\/span><\/span><\/span>serem ambas aud\u00edveis. <\/b><\/span><\/span><\/span><\/p>\n

C) <\/b><\/span><\/span><\/span>terem intensidades inversas.<\/b><\/span><\/span><\/span><\/p>\n

D) <\/b><\/span><\/span><\/span>serem de mesma amplitude. <\/b><\/span><\/span><\/span><\/p>\n

E) <\/b><\/span><\/span><\/span>terem frequ\u00eancias pr\u00f3ximas.<\/b><\/span><\/span><\/span><\/p>\n

06-(ENEM-MEC)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma <\/b><\/span><\/span><\/span>manifesta\u00e7\u00e3o comum das torcidas <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>est\u00e1dios de futebol \u00e9 a\u00a0ola mexicana. <\/b><\/span><\/span><\/span><\/p>\n

Os espectadores de uma linha, sem sair do lugar e sem se deslocarem lateralmente,\u00a0ficam de p\u00e9 e se sentam, sincronizados com os da linha adjacente. O efeito coletivo se propaga pelos espectadores do est\u00e1dio, formando uma onda progressiva, conforme ilustra\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Calcula-se que a\u00a0velocidade\u00a0de propaga\u00e7\u00e3o dessa \u201conda humana\u201d \u00e9 de\u00a045 km\/h,\u00a0e que cada\u00a0per\u00edodo\u00a0de<\/b><\/span><\/span><\/span><\/p>\n

Oscila\u00e7\u00e3o\u00a0cont\u00e9m 16 pessoas,\u00a0que se levantam e sentam organizadamente e\u00a0distanciadas entre si por 80cm.Dispon\u00edvel em: www.ufsm.br. Acesso em: 7 dez. 2012 (adaptado).<\/b><\/span><\/span><\/span><\/p>\n

Nessa ola mexicana, a\u00a0frequ\u00eancia da onda, em hertz, \u00e9 um valor mais pr\u00f3ximo de<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

07-(FUVEST-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>Sr.Rubinato, <\/b><\/span><\/span><\/span>um <\/b><\/span><\/span><\/span>m\u00fasico aposentado, <\/b><\/span><\/span><\/span>gosta de ouvir <\/b><\/span><\/span><\/span>seus velhos discos sentado em uma poltrona.<\/b><\/span><\/span><\/span><\/p>\n

Est\u00e1 <\/b><\/span><\/span><\/span>ouvindo um conhecido solo de violino <\/b><\/span><\/span><\/span>quando sua <\/b><\/span><\/span><\/span>esposa Matilde\u00a0<\/b><\/span><\/span><\/span>afasta a <\/b><\/span><\/span><\/span>caixa ac\u00fastica da direita (C<\/b><\/span><\/span><\/span>d<\/b><\/span><\/span><\/sub><\/span>)\u00a0de uma dist\u00e2ncia\u00a0\u2113, como visto na figura abaixo.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Em seguida, <\/b><\/span><\/span><\/span>Sr. Rubinato reclama: N\u00e3o consigo <\/b><\/span><\/span><\/span>mais ouvir o <\/b><\/span><\/span><\/span>L\u00e1 do violino, que antes soava bastante forte!<\/b><\/span><\/span><\/span><\/p>\n

Dentre as <\/b><\/span><\/span><\/span>alternativas abaixo <\/b><\/span><\/span><\/span>para a <\/b><\/span><\/span><\/span>dist\u00e2ncia L, <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>\u00fanica compat\u00edvel <\/b><\/span><\/span><\/span>com a <\/b><\/span><\/span><\/span>reclama\u00e7\u00e3o do Sr. Rubinato \u00e9<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>38cm <\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>44cm <\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>60cm <\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>75cm <\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>150cm<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

08-(FUVEST-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>resultado do exame de audiometria <\/b><\/span><\/span><\/span>de uma pessoa \u00e9 <\/b><\/span><\/span><\/span>mostrado nas figuras abaixo. <\/b><\/span><\/span><\/span><\/p>\n

Os <\/b><\/span><\/span><\/span>gr\u00e1ficos representam o n\u00edvel de intensidade sonora m\u00ednima I, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>decib\u00e9is (dB), aud\u00edvel <\/b><\/span><\/span><\/span>por <\/b><\/span><\/span><\/span>suas orelhas direita e esquerda, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>fun\u00e7\u00e3o da frequ\u00eancia f do som, em kHz.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

A <\/b><\/span><\/span><\/span>compara\u00e7\u00e3o <\/b><\/span><\/span><\/span>desse resultado <\/b><\/span><\/span><\/span>com o de exames anteriores <\/b><\/span><\/span><\/span>mostrou que, com o <\/b><\/span><\/span><\/span>passar dos anos, ela teve perda auditiva. <\/b><\/span><\/span><\/span>Com <\/b><\/span><\/span><\/span>base nessas<\/b><\/span><\/span><\/span> <\/b>informa\u00e7\u00f5es, <\/b><\/span><\/span><\/span>foram <\/b><\/span><\/span><\/span>feitas as seguintes afirma\u00e7\u00f5es <\/b><\/span><\/span><\/span>sobre a <\/b><\/span><\/span><\/span>audi\u00e7\u00e3o <\/b><\/span><\/span><\/span>dessa pessoa:<\/b><\/span><\/span><\/span><\/p>\n

I. <\/b><\/span><\/span><\/span>Ela <\/b><\/span><\/span><\/span>ouve<\/b><\/span><\/span><\/span> <\/b>sons de frequ\u00eancia de 6 kHz <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>intensidade de 20 dB <\/b><\/span><\/span><\/span>com a <\/b><\/span><\/span><\/span>orelha direita, <\/b><\/span><\/span><\/span>mas <\/b><\/span><\/span><\/span>n\u00e3o<\/b><\/span><\/span><\/span> com a <\/b><\/span><\/span><\/span>esquerda.<\/b><\/span><\/span><\/span><\/p>\n

II. <\/b><\/span><\/span><\/span>Um <\/b><\/span><\/span><\/span>sussurro de 15 dB e frequ\u00eancia de 0,25 kHz \u00e9 ouvido por ambas as orelhas.<\/b><\/span><\/span><\/span><\/p>\n

III. <\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>diminui\u00e7\u00e3o de sua sensibilidade auditiva<\/b><\/span><\/span><\/span>, com o <\/b><\/span><\/span><\/span>passar do tempo,<\/b><\/span><\/span><\/span> pode ser <\/b><\/span><\/span><\/span>atribu\u00edda a degenera\u00e7\u00f5es<\/b><\/span><\/span><\/span> <\/b>dos <\/b><\/span><\/span><\/span>ossos martelo, bigorna e estribo, da orelha externa, onde ocorre a convers\u00e3o do som em impulsos el\u00e9tricos.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u00c9 <\/b><\/span><\/span><\/span>correto <\/b><\/span><\/span><\/span>apenas <\/b><\/span><\/span><\/span>o que se afirma <\/b><\/span><\/span><\/span>em<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

09-(UNESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Duas <\/b><\/span><\/span><\/span>ondas mec\u00e2nicas transversais <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>id\u00eanticas, I e II, <\/b><\/span><\/span><\/span>propagam-se em <\/b><\/span><\/span><\/span>sentidos opostos por uma corda el\u00e1stica tracionada.<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>figura 1 <\/b><\/span><\/span><\/span>representa as <\/b><\/span><\/span><\/span>deforma\u00e7\u00f5es que a onda I, <\/b><\/span><\/span><\/span>que se <\/b><\/span><\/span><\/span>propaga para direita, <\/b><\/span><\/span><\/span>provocaria <\/b><\/span><\/span><\/span>em<\/b><\/span><\/span><\/span> um <\/b><\/span><\/span><\/span>trecho da corda nos instantes t = 0 e t = T\/4,<\/b><\/span><\/span><\/span> em que <\/b><\/span><\/span><\/span>T \u00e9 o per\u00edodo de oscila\u00e7\u00e3o das duas ondas. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>figura 2 <\/b><\/span><\/span><\/span>representa as <\/b><\/span><\/span><\/span>deforma\u00e7\u00f5es que a onda II, <\/b><\/span><\/span><\/span>que se <\/b><\/span><\/span><\/span>propaga para esquerda, <\/b><\/span><\/span><\/span>provocaria no <\/b><\/span><\/span><\/span>mesmo trecho da corda, nos mesmos instantes relacionados na figura 1.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ao <\/b><\/span><\/span><\/span>se cruzarem,<\/b><\/span><\/span><\/span> essas ondas <\/b><\/span><\/span><\/span>produzem uma figura de interfer\u00eancia <\/b><\/span><\/span><\/span>e, devido a esse <\/b><\/span><\/span><\/span>fen\u00f4meno,<\/b><\/span><\/span><\/span> <\/b>estabelece-se <\/b><\/span><\/span><\/span>uma <\/b><\/span><\/span><\/span>onda estacion\u00e1ria na corda. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>figura 3 <\/b><\/span><\/span><\/span>representa a <\/b><\/span><\/span><\/span>configura\u00e7\u00e3o da corda resultante <\/b><\/span><\/span><\/span>da <\/b><\/span><\/span><\/span>interfer\u00eancia dessas duas ondas, <\/b><\/span><\/span><\/span>nos <\/b><\/span><\/span><\/span>mesmos instantes t = 0 e t=T\/4.<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>figura <\/b><\/span><\/span><\/span>que <\/b><\/span><\/span><\/span>melhor representa <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>configura\u00e7\u00e3o da corda <\/b><\/span><\/span><\/span>nesse <\/b><\/span><\/span><\/span>mesmo trecho devido <\/b><\/span><\/span><\/span>\u00e0 forma\u00e7\u00e3o da <\/b><\/span><\/span><\/span>onda estacion\u00e1ria, no instante 3T\/4, <\/b><\/span><\/span><\/span>est\u00e1 <\/b><\/span><\/span><\/span>representada <\/b><\/span><\/span><\/span>na alternativa<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

10-(UNESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Observe o\u00a0<\/b><\/span><\/span><\/span>espectro de radia\u00e7\u00e3o eletromagn\u00e9tica <\/b><\/span><\/span><\/span>com a <\/b><\/span><\/span><\/span>por\u00e7\u00e3o vis\u00edvel <\/b><\/span><\/span><\/span>pelo <\/b><\/span><\/span><\/span>ser humano\u00a0em destaque. <\/b><\/span><\/span><\/span>A\u00a0<\/b><\/span><\/span><\/span>cor da luz vis\u00edvel\u00a0<\/b><\/span><\/span><\/span>ao ser <\/b><\/span><\/span><\/span>humano \u00e9 determinada pela\u00a0frequ\u00eancia \u03bd, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>hertz (Hz).\u00a0<\/b><\/span><\/span><\/span><\/p>\n

No\u00a0<\/b><\/span><\/span><\/span>espectro,<\/b><\/span><\/span><\/span> a\u00a0<\/b><\/span><\/span><\/span>unidade de comprimento de onda\u00a0\u03bb <\/b><\/span><\/span><\/span>\u00e9 o <\/b><\/span><\/span><\/span>metro (m) <\/b><\/span><\/span><\/span>e, no <\/b><\/span><\/span><\/span>destaque,<\/b><\/span><\/span><\/span> \u00e9 o <\/b><\/span><\/span><\/span>nan\u00f4metro (nm).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Sabendo que\u00a0a\u00a0<\/b><\/span><\/span><\/span>frequ\u00eancia \u03bd\u00a0\u00e9 inversamente proporcional ao\u00a0comprimento de onda \u03bb, <\/b><\/span><\/span><\/span>sendo a\u00a0<\/b><\/span><\/span><\/span>constante de proporcionalidade igual \u00e0 velocidade da luz no v\u00e1cuo\u00a0<\/b><\/span><\/span><\/span>de, aproximadamente,<\/b><\/span><\/span><\/span><\/p>\n

3,0.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>\u00a0m\/s, e que\u00a01 nan\u00f4metro equivale a 1,0.10<\/b><\/span><\/span><\/span>-9<\/b><\/span><\/span><\/sup><\/span>\u00a0m, <\/b><\/span><\/span><\/span>pode-se <\/b><\/span><\/span><\/span>deduzir que a\u00a0frequ\u00eancia da cor, <\/b><\/span><\/span><\/span>no\u00a0<\/b><\/span><\/span><\/span>ponto do destaque indicado pela flecha, em Hz,<\/b><\/span><\/span><\/span> <\/b>vale <\/b><\/span><\/span><\/span>aproximadamente<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

11-(ACAFE-SC)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Na <\/b><\/span><\/span><\/span>medicina os raios X\u00a0s\u00e3o utilizados <\/b><\/span><\/span><\/span>nas <\/b><\/span><\/span><\/span>an\u00e1lises<\/b><\/span><\/span><\/span> das\u00a0<\/b><\/span><\/span><\/span>condi\u00e7\u00f5es dos \u00f3rg\u00e3os internos,<\/b><\/span><\/span><\/span> pesquisas<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

de fraturas, tratamento de tumores, c\u00e2ncer (ou cancro), doen\u00e7as \u00f3sseas, etc.\u00a0<\/b><\/span><\/span><\/span><\/p>\n

Raios X\u00a0<\/b><\/span><\/span><\/span>s\u00e3o <\/b><\/span><\/span><\/span>basicamente o\u00a0mesmo que os raios de luz vis\u00edveis, <\/b><\/span><\/span><\/span>ou seja, <\/b><\/span><\/span><\/span>formado <\/b><\/span><\/span><\/span>por <\/b><\/span><\/span><\/span>ondas eletromagn\u00e9ticas <\/b><\/span><\/span><\/span>que se <\/b><\/span><\/span><\/span>propagam no v\u00e1cuo \u00e0 velocidade da luz.<\/b><\/span><\/span><\/span><\/p>\n

Em rela\u00e7\u00e3o aos\u00a0<\/b><\/span><\/span><\/span>raios X, analise as afirma\u00e7\u00f5es<\/b><\/span><\/span><\/span> a seguir.<\/b><\/span><\/span><\/span><\/p>\n

l.\u00a0<\/b><\/span><\/span><\/span>Os <\/b><\/i><\/span><\/span><\/span>raios X est\u00e3o sujeitos <\/b><\/i><\/span><\/span><\/span>ao <\/b><\/i><\/span><\/span><\/span>fen\u00f4meno da reflex\u00e3o, refra\u00e7\u00e3o, difra\u00e7\u00e3o e interfer\u00eancia.<\/b><\/i><\/span><\/span><\/span><\/p>\n

ll.\u00a0<\/b><\/span><\/span><\/span>Sua <\/b><\/i><\/span><\/span><\/span>penetr\u00e2ncia nos materiais \u00e9 relevante, <\/b><\/i><\/span><\/span><\/span>pois <\/b><\/i><\/span><\/span><\/span>todas<\/b><\/i><\/span><\/span><\/span> as <\/b><\/i><\/span><\/span><\/span>subst\u00e2ncias<\/b><\/i><\/span><\/span><\/span> s\u00e3o <\/b><\/i><\/span><\/span><\/span>penetradas pelos raios<\/b><\/i><\/span><\/span><\/span><\/p>\n

X em maior ou menor grau.<\/b><\/i><\/span><\/span><\/span><\/p>\n

Ill.\u00a0<\/b><\/span><\/span><\/span>Por estar <\/b><\/i><\/span><\/span><\/span>sujeito \u00e0 reflex\u00e3o, os raios X n\u00e3o penetram os ossos.<\/b><\/i><\/span><\/span><\/span><\/p>\n

lV.\u00a0<\/b><\/span><\/span><\/span>A <\/b><\/i><\/span><\/span><\/span>diferen\u00e7a entre raios X <\/b><\/i><\/span><\/span><\/span>e <\/b><\/i><\/span><\/span><\/span>raios de luz vis\u00edvel <\/b><\/i><\/span><\/span><\/span>\u00e9 devida ao <\/b><\/i><\/span><\/span><\/span>comprimento de onda diferente dos<\/b><\/i><\/span><\/span><\/span><\/p>\n

mesmos.<\/b><\/i><\/span><\/span><\/span><\/p>\n

Todas\u00a0as <\/b><\/span><\/span><\/span>afirma\u00e7\u00f5es\u00a0corretas\u00a0<\/b><\/span><\/span><\/span>est\u00e3o em:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

12-(CEDERJ-RJ)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>Figura 1<\/b><\/span><\/span><\/span> ilustra\u00a0<\/b><\/span><\/span><\/span>duas fotos tiradas de uma corda na qual uma onda se propaga para a direita.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

A <\/b><\/span><\/span><\/span>primeira foto, <\/b><\/span><\/span><\/span>representada pela\u00a0<\/b><\/span><\/span><\/span>curva cont\u00ednua, <\/b><\/span><\/span><\/span>foi <\/b><\/span><\/span><\/span>tirada<\/b><\/span><\/span><\/span> no <\/b><\/span><\/span><\/span>instante de tempo\u00a0t = 0\u00a0<\/b><\/span><\/span><\/span>e a\u00a0<\/b><\/span><\/span><\/span>segunda, <\/b><\/span><\/span><\/span>representada pela <\/b><\/span><\/span><\/span>curva tracejada, foi tirada em um instante de tempo posterior,\u00a0t = t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>. <\/b><\/span><\/span><\/span>A\u00a0<\/b><\/span><\/span><\/span>coordenada\u00a0vertical <\/b><\/span><\/span><\/span>descreve os\u00a0<\/b><\/span><\/span><\/span>deslocamentos dos pontos da corda em rela\u00e7\u00e3o \u00e0s suas posi\u00e7\u00f5es de equil\u00edbrio,\u00a0que coincidem com o eixo horizontal com\u00a0coordenada x (em metros).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>Figura 2 ilustra o resultado de uma filmagem <\/b><\/span><\/span><\/span>e mostra o\u00a0<\/b><\/span><\/span><\/span>deslocamento vertical <\/b><\/span><\/span><\/span>do <\/b><\/span><\/span><\/span>ponto da corda <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>coordenada x = 0 em fun\u00e7\u00e3o do\u00a0tempo t (em segundos).<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>Determine o <\/b><\/span><\/span><\/span>valor\u00a0do comprimento da onda<\/b><\/span><\/span><\/span>, especificando\u00a0a <\/b><\/span><\/span><\/span>figura (1 ou 2)\u00a0da qual a informa\u00e7\u00e3o foi extra\u00edda.<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>Determine o <\/b><\/span><\/span><\/span>valor do\u00a0per\u00edodo da onda,\u00a0especificando a\u00a0figura (1 ou 2)\u00a0da qual a informa\u00e7\u00e3o foi extra\u00edda.<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>Encontre o\u00a0<\/b><\/span><\/span><\/span>valor m\u00ednimo de t<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

13-(UFSCAR-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Para o <\/b><\/span><\/span><\/span>estudo do compasso musical <\/b><\/span><\/span><\/span>abaixo,\u00a0o <\/b><\/span><\/span><\/span>metr\u00f4nomo<\/b><\/span><\/span><\/span>\u00a0(aparelho que emite sons produzidos por batidas regulares controladas pelo oscilar de um p\u00eandulo) <\/b><\/span><\/span><\/span>deve estar\u00a0ajustado para emitir 60 batidas no tempo de um minuto.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Devido \u00e0 <\/b><\/span><\/span><\/span>indica\u00e7\u00e3o 4\/4 escrita na partitura,<\/b><\/span><\/span><\/span> as\u00a0<\/b><\/span><\/span><\/span>8 notas\u00a0do compasso musical <\/b><\/span><\/span><\/span>(todas de igual dura\u00e7\u00e3o sonora) <\/b><\/span><\/span><\/span>devem ser tocadas <\/b><\/span><\/span><\/span>no\u00a0<\/b><\/span><\/span><\/span>tempo de quatro batidas do metr\u00f4nomo.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Em <\/b><\/span><\/span><\/span>outras palavras, <\/b><\/span><\/span><\/span>utilizando-se a <\/b><\/span><\/span><\/span>unidade de tempo do Sistema Internacional, <\/b><\/span><\/span><\/span>cada nota reproduzida <\/b><\/span><\/span><\/span>deve demorar o tempo, em s<\/b><\/span><\/span><\/span>, de<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

14-(UCS-RS)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>importante componente<\/b><\/span><\/span><\/span> para um <\/b><\/span><\/span><\/span>filme \u00e9 sua\u00a0trilha sonora.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Alguns sons, <\/b><\/span><\/span><\/span>inclusive, j\u00e1 est\u00e3o <\/b><\/span><\/span><\/span>associados a certas\u00a0emo\u00e7\u00f5es <\/b><\/span><\/span><\/span>que se <\/b><\/span><\/span><\/span>desejam passar ao espectador em\u00a0uma cena.\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Por exemplo, em<\/b><\/span><\/span><\/span> <\/b>filmes de terror e mist\u00e9rio, <\/b><\/span><\/span><\/span>\u00e9 <\/b><\/span><\/span><\/span>comum<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>som de fundo da cena ser\u00a0mais grave <\/b><\/span><\/span><\/span>(embora haja exce\u00e7\u00f5es).\u00a0<\/b><\/span><\/span><\/span><\/p>\n

Imagine-se uma <\/b><\/span><\/span><\/span>pessoa cuja percep\u00e7\u00e3o sonora <\/b><\/span><\/span><\/span>a permite <\/b><\/span><\/span><\/span>distinguir os sons graves e agudos emitidos por um instrumento musical.<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/p>\n

Se ela <\/b><\/span><\/span><\/span>receber<\/b><\/span><\/span><\/span> do <\/b><\/span><\/span><\/span>mesmo aparelho <\/b><\/span><\/span><\/span>de som em <\/b><\/span><\/span><\/span>sequ\u00eancia,<\/b><\/span><\/span><\/span> e <\/b><\/span><\/span><\/span>sem que ocorra nenhuma mudan\u00e7a <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>meio de propaga\u00e7\u00e3o da onda,\u00a0<\/b><\/span><\/span><\/span>primeiro uma <\/b><\/span><\/span><\/span>onda sonora que ela classifica como de som grave, e depois uma onda sonora que ela classifica como de som agudo,<\/b><\/span><\/span><\/span> <\/b>significa que <\/b><\/span><\/span><\/span>ela recebeu, respectivamente,<\/b><\/span><\/span><\/span><\/p>\n

a) duas ondas mec\u00e2nicas,<\/b><\/span><\/span><\/span> sendo a <\/b><\/span><\/span><\/span>primeira com frequ\u00eancia menor do que a segunda.<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>uma <\/b><\/span><\/span><\/span>onda eletromagn\u00e9tica de pequeno comprimento de onda <\/b><\/span><\/span><\/span>e uma <\/b><\/span><\/span><\/span>onda mec\u00e2nica de grande comprimento de onda.<\/b><\/span><\/span><\/span><\/p>\n

c) duas ondas eletromagn\u00e9ticas <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>iguais frequ\u00eancias <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>diferentes comprimentos de onda.<\/b><\/span><\/span><\/span><\/p>\n

d) duas ondas mec\u00e2nicas <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>iguais comprimentos de onda e diferentes frequ\u00eancias.<\/b><\/span><\/span><\/span><\/p>\n

e) duas ondas mec\u00e2nicas <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>iguais frequ\u00eancias,<\/b><\/span><\/span><\/span> <\/b>iguais comprimentos de onda, <\/b><\/span><\/span><\/span>mas <\/b><\/span><\/span><\/span>diferentes amplitudes.<\/b><\/span><\/span><\/span><\/p>\n

15-(UEA-AM)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>gr\u00e1fico <\/b><\/span><\/span><\/span>representa as <\/b><\/span><\/span><\/span>varia\u00e7\u00f5es da press\u00e3o sangu\u00ednea <\/b><\/span><\/span><\/span>em uma <\/b><\/span><\/span><\/span>art\u00e9ria do bra\u00e7o de um homem saud\u00e1vel, <\/b><\/span><\/span><\/span>durante <\/b><\/span><\/span><\/span>cinco segundos. <\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>seta 1 <\/b><\/span><\/span><\/span>indica a <\/b><\/span><\/span><\/span>s\u00edstole<\/b><\/span><\/span><\/span> e a <\/b><\/span><\/span><\/span>2, a di\u00e1stole.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Utilizando as <\/b><\/span><\/span><\/span>escalas representadas no gr\u00e1fico,<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>valor aproximado <\/b><\/span><\/span><\/span>da <\/b><\/span><\/span><\/span>frequ\u00eancia card\u00edaca <\/b><\/span><\/span><\/span>desse homem <\/b><\/span><\/span><\/span>(batimentos\/minuto), <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>momento da medi\u00e7\u00e3o,<\/b><\/span><\/span><\/span> era de<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

16-(UEL-PR)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>polui\u00e7\u00e3o sonora <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>grandes cidades <\/b><\/span><\/span><\/span>\u00e9 um <\/b><\/span><\/span><\/span>problema de sa\u00fade p\u00fablica. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>classifica\u00e7\u00e3o do som <\/b><\/span><\/span><\/span>como <\/b><\/span><\/span><\/span>forte ou fraco <\/b><\/span><\/span><\/span>est\u00e1 relacionada ao <\/b><\/span><\/span><\/span>n\u00edvel de intensidade sonora, <\/b><\/span><\/span><\/span>medido em <\/b><\/span><\/span><\/span>watt\/m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>menor intensidade aud\u00edvel, <\/b><\/span><\/span><\/span>ou <\/b><\/span><\/span><\/span>limiar de audibilidade, <\/b><\/span><\/span><\/span>possui <\/b><\/span><\/span><\/span>intensidade\u00a0I<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>\u00a0= 10<\/b><\/span><\/span><\/span>-12<\/b><\/span><\/span><\/sup><\/span>\u00a0watt\/m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>, <\/b><\/span><\/span><\/span>para a <\/b><\/span><\/span><\/span>frequ\u00eancia de 1000 Hz. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>rela\u00e7\u00e3o<\/b><\/span><\/span><\/span> entre as <\/b><\/span><\/span><\/span>intensidades sonoras <\/b><\/span><\/span><\/span>permite calcular o <\/b><\/span><\/span><\/span>n\u00edvel sonoro,\u00a0NS, <\/b><\/span><\/span><\/span>do <\/b><\/span><\/span><\/span>ambiente,<\/b><\/span><\/span><\/span> em <\/b><\/span><\/span><\/span>decib\u00e9is (dB), <\/b><\/span><\/span><\/span>dado pela <\/b><\/span><\/span><\/span>f\u00f3rmula\u00a0NS=10.log(I\/I<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>).<\/b><\/span><\/span><\/span><\/p>\n

\u00a0<\/span>A <\/b><\/span><\/span><\/span>tabela a seguir <\/b><\/span><\/span><\/span>mostra a <\/b><\/span><\/span><\/span>rela\u00e7\u00e3o do n\u00edvel sonoro com o tempo m\u00e1ximo de exposi\u00e7\u00e3o a ru\u00eddos.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Com <\/b><\/span><\/span><\/span>base nessa tabela, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>text<\/b><\/span><\/span><\/span>o e supondo que o <\/b><\/span><\/span><\/span>ru\u00eddo em uma avenida com tr\u00e2nsito congestionado <\/b><\/span><\/span><\/span>tenha<\/b><\/span><\/span><\/span> <\/b>intensidade de\u00a010<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>\u00a0watt\/m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>, considere as <\/b><\/span><\/span><\/span>afirmativas<\/b><\/span><\/span><\/span> a seguir.<\/b><\/span><\/span><\/span><\/p>\n

I. O n\u00edvel sonoro para um ru\u00eddo <\/b><\/span><\/span><\/span>dessa <\/b><\/span><\/span><\/span>intensidade \u00e9 de 90 dB.<\/b><\/span><\/span><\/span><\/p>\n

II. <\/b><\/span><\/span><\/span>O <\/b><\/span><\/span><\/span>tempo m\u00e1ximo<\/b><\/span><\/span><\/span> em <\/b><\/span><\/span><\/span>horas de exposi\u00e7\u00e3o a esse ru\u00eddo<\/b><\/span><\/span><\/span>, a fim de <\/b><\/span><\/span><\/span>evitar les\u00f5es auditivas irrevers\u00edveis, \u00e9 de 4 horas.<\/b><\/span><\/span><\/span><\/p>\n

III. <\/b><\/span><\/span><\/span>Se a <\/b><\/span><\/span><\/span>intensidade sonora considerada for igual ao limiar de audibilidade, <\/b><\/span><\/span><\/span>ent\u00e3o<\/b><\/span><\/span><\/span> <\/b>o <\/b><\/span><\/span><\/span>n\u00edvel sono<\/b><\/span><\/span><\/span>ro \u00e9 de <\/b><\/span><\/span><\/span>1 dB.<\/b><\/span><\/span><\/span><\/p>\n

IV. Sons de intensidade de 1 watt\/m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>correspondem ao <\/b><\/span><\/span><\/span>n\u00edvel sonoro de 100 dB.<\/b><\/span><\/span><\/span><\/p>\n

Assinale a <\/b><\/span><\/span><\/span>alternativa correta<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>Somente as <\/b><\/span><\/span><\/span>afirmativas I e II s\u00e3o corretas. <\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>Somente as <\/b><\/span><\/span><\/span>afirmativas I e IV s\u00e3o corretas.<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>Somente as <\/b><\/span><\/span><\/span>afirmativas III e IV s\u00e3o corretas. <\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>Somente as <\/b><\/span><\/span><\/span>afirmativas I, II e III s\u00e3o corretas.<\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>Somente as <\/b><\/span><\/span><\/span>afirmativas II, III e IV s\u00e3o corretas.<\/b><\/span><\/span><\/span><\/p>\n

17-(UENP-PR)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Deslocando-<\/b><\/span><\/span><\/span>se \u00e0\u00a0velocidade de 144 km\/h\u00a0por uma via<\/b><\/span><\/span><\/span>, uma\u00a0<\/b><\/span><\/span><\/span>viatura da pol\u00edcia rodovi\u00e1ria<\/b><\/span><\/span><\/span>, em <\/b><\/span><\/span><\/span>persegui\u00e7\u00e3o,\u00a0toca a sirene, <\/b><\/span><\/span><\/span>cujo <\/b><\/span><\/span><\/span>som tem\u00a0frequ\u00eancia igual a 1500 Hz.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Uma\u00a0<\/b><\/span><\/span><\/span>mulher parada<\/b><\/span><\/span><\/span>\u00a0num <\/b><\/span><\/span><\/span>ponto<\/b><\/span><\/span><\/span><\/p>\n

de \u00f4nibus, na mesma via<\/b><\/span><\/span><\/span>, percebe uma\u00a0<\/b><\/span><\/span><\/span>varia\u00e7\u00e3o brusca no som, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>instante<\/b><\/span><\/span><\/span> em que a <\/b><\/span><\/span><\/span>viatura passa pelo ponto onde ela se encontra. <\/b><\/span><\/span><\/span>Qual \u00e9, em <\/b><\/span><\/span><\/span>valor aproximado, <\/b><\/span><\/span><\/span>a\u00a0<\/b><\/span><\/span><\/span>varia\u00e7\u00e3o de frequ\u00eancia, em Hz, ouvida pela mulher, <\/b><\/span><\/span><\/span>tendo como <\/b><\/span><\/span><\/span>par\u00e2metro os per\u00edodos anterior e posterior \u00e0 passagem da viatura?<\/b><\/span><\/span><\/span><\/p>\n

Adote a <\/b><\/span><\/span><\/span>velocidade do som\u00a0V<\/b><\/span><\/span><\/span>s<\/b><\/span><\/span><\/sub><\/span>\u00a0= 340m\/s<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

18-(UFU-MG)<\/b><\/span><\/span><\/span><\/p>\n

\u00a0\"\"<\/span><\/p>\n

Em <\/b><\/span><\/span><\/span>algumas cenas de filmes antigos de faroeste,<\/b><\/span><\/span><\/span> os \u00edndios norte-americanos <\/b><\/span><\/span><\/span>detectavam a chegada <\/b><\/span><\/span><\/span>da <\/b><\/span><\/span><\/span>cavalaria dos \u201ccaras p\u00e1lidas\u201d encostando o ouvido no ch\u00e3o. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>figura abaixo ilustra uma situa\u00e7\u00e3o <\/b><\/span><\/span><\/span>em que a <\/b><\/span><\/span><\/span>cavalaria emite um sinal com frequ\u00eancia de 440 Hz <\/b><\/span><\/span><\/span>para <\/b><\/span><\/span><\/span>iniciar o ataque aos \u00edndios<\/b><\/span><\/span><\/span>, os quais a <\/b><\/span><\/span><\/span>esperam do outro lado do lago.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Considere que o <\/b><\/span><\/span><\/span>som se propaga sem atenua\u00e7\u00f5es com velocidade de 319 m\/s no ar, 1.320 m\/s na \u00e1gua e 5.720 m\/s no solo.<\/b><\/span><\/span><\/span><\/p>\n

Com base nas <\/b><\/span><\/span><\/span>informa\u00e7\u00f5es dadas, <\/b><\/span><\/span><\/span>marque, para as <\/b><\/span><\/span><\/span>afirmativas abaixo, (V) Verdadeira, (F) Falsa ou (SO) Sem Op\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

1. <\/b><\/span><\/span><\/span>( ) Os <\/b><\/span><\/span><\/span>\u00edndios ouvir\u00e3<\/b><\/span><\/span><\/span>o o <\/b><\/span><\/span><\/span>sinal de ataque da cavalaria 18,5s antes de colocarem o ouvido no ch\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

2. <\/b><\/span><\/span><\/span>( ) O <\/b><\/span><\/span><\/span>sinal se propaga na \u00e1gua com comprimento de onda de 3m, <\/b><\/span><\/span><\/span>que \u00e9 <\/b><\/span><\/span><\/span>maior do que o comprimento de onda do sinal que se propagaria no solo.<\/b><\/span><\/span><\/span><\/p>\n

3. <\/b><\/span><\/span><\/span>( ) <\/b><\/span><\/span><\/span>Os \u00edndios perceber\u00e3o <\/b><\/span><\/span><\/span>que, com a <\/b><\/span><\/span><\/span>aproxima\u00e7\u00e3o da cavalaria em dire\u00e7\u00e3o \u00e0 margem do lago,<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>som produzido pela tropa ficar\u00e1 mais grave com o passar do tempo.<\/b><\/span><\/span><\/span><\/p>\n

4. <\/b><\/span><\/span><\/span>( ) A <\/b><\/span><\/span><\/span>situa\u00e7\u00e3o idea<\/b><\/span><\/span><\/span>l para a <\/b><\/span><\/span><\/span>propaga\u00e7\u00e3o do som entre os \u00edndios e a cavalaria <\/b><\/span><\/span><\/span>ocorre <\/b><\/span><\/span><\/span>quando existe v\u00e1cuo entre eles<\/b><\/span><\/span><\/span>, pois no <\/b><\/span><\/span><\/span>v\u00e1cuo o som se propaga com velocidade igual \u00e0 da luz, que \u00e9 de 300.000 km<\/b><\/span><\/span><\/span>\/s.<\/b><\/span><\/span><\/span><\/p>\n

19-(UNAMA-PA)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Num\u00a0<\/b><\/span><\/span><\/span>Instituto de oceanografia<\/b><\/span><\/span><\/span>, temos um <\/b><\/span><\/span><\/span>reservat\u00f3rio contendo \u00e1gua,\u00a0<\/b><\/span><\/span><\/span>destinado a <\/b><\/span><\/span><\/span>pesquisas <\/b><\/span><\/span><\/span>sobre\u00a0<\/b><\/span><\/span><\/span>caracter\u00edsticas de ondas. <\/b><\/span><\/span><\/span><\/p>\n

Na <\/b><\/span><\/span><\/span>figura abaixo <\/b><\/span><\/span><\/span>temos um\u00a0<\/b><\/span><\/span><\/span>corte transversal <\/b><\/span><\/span><\/span>desse <\/b><\/span><\/span><\/span>reservat\u00f3rio,<\/b><\/span><\/span><\/span> onde notamos que ele <\/b><\/span><\/span><\/span>apresenta\u00a0tr\u00eas regi\u00f5es com profundidades H e h.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um\u00a0<\/b><\/span><\/span><\/span>dispositivo oscilante <\/b><\/span><\/span><\/span>gera uma <\/b><\/span><\/span><\/span>onda peri\u00f3dica <\/b><\/span><\/span><\/span>a qual se <\/b><\/span><\/span><\/span>propagar\u00e1<\/b><\/span><\/span><\/span> no <\/b><\/span><\/span><\/span>sentido\u00a0da regi\u00e3o I para a regi\u00e3o III, passando pela regi\u00e3o II.<\/b><\/span><\/span><\/span><\/p>\n

Com rela\u00e7\u00e3o <\/b><\/span><\/span><\/span>\u00e0\u00a0onda gerada, <\/b><\/span><\/span><\/span>podemos <\/b><\/span><\/span><\/span>afirmar<\/b><\/span><\/span><\/span> que<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>sua <\/b><\/span><\/span><\/span>frequ\u00eancia nas regi\u00f5es I e III s\u00e3o iguais<\/b><\/span><\/span><\/span>, mas <\/b><\/span><\/span><\/span>diferente<\/b><\/span><\/span><\/span> daquela <\/b><\/span><\/span><\/span>verificada na regi\u00e3o II.<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>velocidade<\/b><\/span><\/span><\/span> da onda na <\/b><\/span><\/span><\/span>regi\u00e3o II \u00e9 maior que as velocidades nas regi\u00f5es I e III.<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>velocidade \u00e9 a mesma nas tr\u00eas regi\u00f5es.<\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>comprimento de onda das regi\u00f5es I e III <\/b><\/span><\/span><\/span>s\u00e3o <\/b><\/span><\/span><\/span>maiores que o comprimento de onda verificado na regi\u00e3o II.<\/b><\/span><\/span><\/span><\/p>\n

20-(UPF-RS)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Em <\/b><\/span><\/span><\/span>2014,<\/b><\/span><\/span><\/span> o Brasil <\/b><\/span><\/span><\/span>sediar\u00e1 a Copa do Mundo de Futebol. <\/b><\/span><\/span><\/span>Em virtude das <\/b><\/span><\/span><\/span>poss\u00edveis manifesta\u00e7\u00f5es <\/b><\/span><\/span><\/span>das<\/b><\/span><\/span><\/span> <\/b>torcidas, <\/b><\/span><\/span><\/span>os <\/b><\/span><\/span><\/span>est\u00e1dios de futebol foram constru\u00eddos de modo a suportar as<\/b><\/span><\/span><\/span> <\/b>vibra\u00e7\u00f5es produzidas.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Se <\/b><\/span><\/span><\/span>todos os torcedores<\/b><\/span><\/span><\/span>, ao <\/b><\/span><\/span><\/span>mesmo tempo<\/b><\/span><\/span><\/span>, come\u00e7arem, por exemplo, a <\/b><\/span><\/span><\/span>pular e a bater os p\u00e9s no ch\u00e3o<\/b><\/span><\/span><\/span>, as <\/b><\/span><\/span><\/span>estruturas das arquibancadas podem desabar, <\/b><\/span><\/span><\/span>provocando uma <\/b><\/span><\/span><\/span>trag\u00e9dia. <\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>fen\u00f4meno f\u00edsico <\/b><\/span><\/span><\/span>que <\/b><\/span><\/span><\/span>melhor descreve a situa\u00e7\u00e3o tr\u00e1gica mencionada \u00e9:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

Confira as resolu\u00e7\u00f5es comentadas e gabaritos<\/span><\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"

Racioc\u00ednio L\u00f3gico Ondulat\u00f3ria Como esse conte\u00fado envolve muita teoria, em caso de d\u00favidas voc\u00ea pode encontr\u00e1-la em\u00a0fisicaevestibular.com.br \u2013 Ondulat\u00f3ria 01-(UEPA-PA) Em uma\u00a0brincadeira infantil\u00a0conhecida como\u00a0\u201ctelefone de barbante\u201d,\u00a0duas crian\u00e7as prendem as extremidades de um barbante, que \u00e9\u00a0mantido esticado, no fundo de dois copos descart\u00e1veis, conforme mostrado na figura abaixo. O funcionamento do brinquedo \u00e9 baseado no fato de que os\u00a0sons produzidos por<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2508,"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-2899","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2899","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=2899"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2899\/revisions"}],"predecessor-version":[{"id":2904,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2899\/revisions\/2904"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2508"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=2899"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}