{"id":2405,"date":"2016-09-11T00:11:12","date_gmt":"2016-09-11T00:11:12","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=2405"},"modified":"2024-08-23T15:10:39","modified_gmt":"2024-08-23T15:10:39","slug":"resolucao-comentada-dos-exercicios-de-vestibulares-sobre-ondas-conceitos-e-definicoes","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/ondulatoria\/ondas\/ondas-conceitos-e-definicoes\/resolucao-comentada-dos-exercicios-de-vestibulares-sobre-ondas-conceitos-e-definicoes\/","title":{"rendered":"Ondas \u2013 Conceitos e defini\u00e7\u00f5es – Resolu\u00e7\u00e3o"},"content":{"rendered":"

Resolu\u00e7\u00e3o comentada dos exerc\u00edcios de vestibulares sobre<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Ondas \u2013 Conceitos e defini\u00e7\u00f5es<\/b><\/span><\/span><\/span><\/p>\n

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

01-\u00a0<\/b><\/span><\/span><\/span><\/p>\n

I \u2013 Errada \u2013 s\u00e3o ondas transversais<\/b><\/span><\/span><\/span><\/p>\n

II \u2013 Verdadeira \u2013 vide voc\u00ea deve saber<\/b><\/span><\/span><\/span><\/p>\n

III \u2013 Errada \u2013 ondas sonoras s\u00e3o ondas mec\u00e2nicas<\/b><\/span><\/span><\/span><\/p>\n

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

02-<\/b><\/span><\/span><\/span> <\/b>B\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

03-<\/b><\/span><\/span><\/span> <\/b>E\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

04- <\/b><\/span><\/span><\/span>E\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

05-<\/b><\/span><\/span><\/span> <\/b>D\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

06-<\/b><\/span><\/span><\/span> <\/b>D\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

07-<\/b><\/span><\/span><\/span> <\/b>D\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\u00a008-\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

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

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

10-<\/b><\/span><\/span><\/span> <\/b>E<\/b><\/span><\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

11-<\/b><\/span><\/span><\/span> <\/b>Para retornar ao equil\u00edbrio o ponto B dever\u00e1 se deslocar de\u00a0\u0394S<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = 60cm = 0,6m\u00a0 —\u00a0 V = \u0394S<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>\/\u0394t\u00a0 —\u00a0 V = 0,6\/t<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Para retornar ao equil\u00edbrio o ponto A dever\u00e1 se deslocar de\u00a0\u0394S<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> = 80cm = 0,8m\u00a0 — V=\u00a0\u0394S<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> \/t<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0 —\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

V= 0,8\/t<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Como a velocidade \u00e9 a mesma para os dois pontos\u00a0 —\u00a0 0,6\/t<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = 0,8\/t<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0 —\u00a0 t<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\/t<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = 4\/3<\/b><\/span><\/span><\/span><\/p>\n

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

12-<\/b><\/span><\/span><\/span> <\/b>a) Deslocamento do pulso em 2s\u00a0 —\u00a0\u00a0DS=20cm=0,2m\u00a0 —\u00a0 V=DS\/Dt\u00a0 —\u00a0 V=0,2\/2\u00a0 —\u00a0 V=0,1m\/s ou V=10cm\/s\u00a0<\/b><\/span><\/span><\/span><\/p>\n

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

\"\"<\/p>\n

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

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

Observe a figura onde est\u00e1 representado o instante\u00a0 em que as ondas est\u00e3o totalmente sobrepostas\u00a0 —\u00a0 haver\u00e1 interfer\u00eancia construtiva na metade esquerda do intervalo e destrutiva na metade direita do mesmo intervalo.<\/b><\/span><\/span><\/span><\/p>\n

\u00a0 \u00a0R- C<\/b><\/span><\/span><\/span><\/p>\n

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

14-\u00a0<\/b><\/span><\/span><\/span>Como o som vai e volta ele percorre \u2206S=2h\u00a0 —\u00a0 V=\u2206S\/\u2206t\u00a0 —1,6.10<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>\u00a0= 2h\/0,8\u00a0 —\u00a0 h=1,6.10<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>.0,4\u00a0 —\u00a0 h=640m.<\/b><\/span><\/span><\/span><\/p>\n

Equa\u00e7\u00e3o fundamental da ondulat\u00f3ria\u00a0 —\u00a0 V=\u03bb.f\u00a0 —\u00a0 1,6.10<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>= \u03bb.4.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0 \u03bb=1,6.10<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>\/4.10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0 \u03bb=0,4.<\/b><\/span><\/span><\/span><\/p>\n

10<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span>=4.10<\/b><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/sup><\/span>m.<\/b><\/span><\/span><\/span><\/p>\n

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

15-(UNEMAT-MT)<\/b><\/span><\/span><\/span><\/p>\n

\u00a0A ultra-sonografia \u00e9 uma t\u00e9cnica de diagn\u00f3stico baseada em imagens, que utiliza ultra-som (onda mec\u00e2nica longitudinal) para visualizar m\u00fasculos e \u00f3rg\u00e3os internos, seu tamanho, estrutura e poss\u00edveis patologias ou les\u00f5es\u00a0 — \u00a0\u00e9<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

comumente usada da obstetr\u00edcia e durante a gravidez\u00a0 —\u00a0 existe uma vasta gama de usos diagn\u00f3sticos para a ultra-sonografia\u00a0 —\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\u00a0R- B.<\/b><\/span><\/span><\/span><\/p>\n

16-<\/b><\/span><\/span><\/span>\u00a0Raio, rel\u00e2mpago e trov\u00e3o s\u00e3o fen\u00f4menos atmosf\u00e9ricos que ocorrem antes ou durante tempestades, causados por descargas el\u00e9tricas entre nuvens ( rel\u00e2mpago ) ou entre uma nuvem e o solo ( raio ), acompanhados de um estrondo ( trov\u00e3o )\u00a0 —\u00a0 o raio ocorre quando uma nuvem, carregada de eletricidade est\u00e1tica, atinge um potencial eletrost\u00e1tico t\u00e3o elevado que a camada de ar existente entre ela e o solo deixa de ser isolante, tornando-se condutor, permitindo a movimenta\u00e7\u00e3o das cargas el\u00e9tricas at\u00e9 o solo\u00a0 —\u00a0 com o rel\u00e2mpago ocorre a mesma coisa s\u00f3 que \u00e9 entre as nuvens\u00a0 —\u00a0\u00a0 essas descargas el\u00e9tricas produzem uma grande luminosidade devido ao aquecimento do ar, que pode ser vista bem distante\u00a0 —\u00a0\u00a0 o trov\u00e3o \u00e9 o som que acompanha a violenta expans\u00e3o do ar quando \u00e9 rapidamente aquecido\u00a0 —\u00a0 devido \u00e0 diferen\u00e7a de velocidades da luz e do som (luz, 3.108m\/s e som, 340m\/s), quando o raio ou rel\u00e2mpago ocorre a grande dist\u00e2ncia do local de observa\u00e7\u00e3o, o trov\u00e3o \u00e9 ouvido alguns segundos depois do clar\u00e3o\u00a0 —\u00a0\u00a0R- E.<\/b><\/span><\/span><\/p>\n

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

\u00a0Observe na figura que o comprimento de onda \u03bb vale \u03bb=60 + 60=120cm=1,2m e que a amplitude A \u00e9 de A=30\/2\u00a0 — A=15cm\u00a0 —\u00a0 A=0,15m\u00a0 —\u00a0 c\u00e1lculo do per\u00edodo T da onda\u00a0 —\u00a0 equa\u00e7\u00e3o fundamental da ondulat\u00f3ria\u00a0 —\u00a0 V= \u03bb.f\u00a0 —\u00a0 120\/\u03c0 = 0,12.f\u00a0 —\u00a0 f=100\/\u03c0Hz\u00a0 —\u00a0 T=1\/f\u00a0 —\u00a0 T=1\/(100\/\u03c0)\u00a0 —\u00a0 T=\u03c0\/100 s\u00a0 —\u00a0 velocidade angular\u00a0 —\u00a0 W=2\u03c0\/T\u00a0 —<\/b><\/span><\/span><\/span>\"\"<\/p>\n

W=2\u03c0\/(100\/\u03c0)\u00a0 —\u00a0 W=200 rad\/s\u00a0 —\u00a0 esse movimento pode ser considerado um movimento harm\u00f4nico simples (MHS), com velocidade angular W e amplitude A e, cuja acelera\u00e7\u00e3o m\u00e1xima \u00e9 fornecida por (veja fisicaevestibular.com.br \u2013 mec\u00e2nica \u2013 din\u00e2mica \u2013 MHS)\u00a0 —\u00a0 a<\/b><\/span><\/span><\/span>m\u00e1x<\/b><\/span><\/span><\/sub><\/span>=W<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>.A=200<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>.0,15=40000×0,15\u00a0 —\u00a0 a<\/b><\/span><\/span><\/span>m\u00e1x<\/b><\/span><\/span><\/sub><\/span>=6000m\/s<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0R- D.<\/b><\/span><\/span><\/span><\/p>\n

18- <\/b><\/span><\/span><\/span>Frequ\u00eancia de 20Hz\u00a0 —\u00a0 V=\u03b3f\u00a0 —\u00a0 340=\u03b3.20\u00a0 —\u00a0 \u03b3=17m\u00a0 —\u00a0 frequ\u00eancia de 20.000Hz\u00a0 —\u00a0 \u03b3=340\/20.000=0,017m\u00a0 —\u00a0\u00a0R- D<\/b><\/span><\/span><\/span><\/p>\n

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

19-<\/b><\/span><\/span><\/span> <\/b>I. Correta\u00a0 —\u00a0 por exemplo, \u00a0a luz \u00e9 uma onda eletromagn\u00e9tica (n\u00e3o precisa de meio material para se propagar) transversal (dire\u00e7\u00e3o de propaga\u00e7\u00e3o \u00e9 perpendicular \u00e0 dire\u00e7\u00e3o de oscila\u00e7\u00e3o).<\/b><\/span><\/span><\/span><\/p>\n

II. Correta\u00a0 — \u00a0varia\u00e7\u00f5es no campo magn\u00e9tico produzem campos el\u00e9tricos vari\u00e1veis que, por sua vez, produzem campos magn\u00e9ticos tamb\u00e9m vari\u00e1veis e assim por diante, permitindo que energia e informa\u00e7\u00f5es sejam transmitidas a grandes dist\u00e2ncias atrav\u00e9s das ondas eletromagn\u00e9ticas que se propagam no v\u00e1cuo com velocidade constante de 3,0.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>m\/s,, inclusive a luz<\/b><\/span><\/span><\/span><\/p>\n

III. Correta\u00a0 — \u00a0Onda n\u00e3o transporta mat\u00e9ria, apenas energia.<\/b><\/span><\/span><\/span><\/p>\n

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

20-<\/b><\/span><\/span><\/span> <\/b>I. Correta\u00a0 —\u00a0 essas tr\u00eas grandezas s\u00e3o escalares, pois ficam perfeitamente caracterizadas apenas pela intensidade acrescida de unidade, n\u00e3o precisando nem de dire\u00e7\u00e3o e nem de sentido.<\/b><\/span><\/span><\/span><\/p>\n

II. Correta\u00a0 —\u00a0 O valor do campo gravitacional g n\u00e3o depende da massa m do corpo, mas apenas de sua posi\u00e7\u00e3o r em rela\u00e7\u00e3o ao centro planeta e da massa M do planeta\u00a0 —\u00a0 voc\u00ea pode fazer analogia do campo gravitacional com os campos magn\u00e9tico e el\u00e9trico..<\/b><\/span><\/span><\/span><\/p>\n

III. Falsa\u00a0 —\u00a0 no estudo das ondas entra a grandeza velocidade que \u00e9 uma grandeza vetorial, pois al\u00e9m de intensidade com unidade, possui tamb\u00e9m dire\u00e7\u00e3o e sentido.<\/b><\/span><\/span><\/span><\/p>\n

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

 <\/p>\n

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

Resolu\u00e7\u00e3o comentada dos exerc\u00edcios de vestibulares sobre Ondas \u2013 Conceitos e defini\u00e7\u00f5es \u00a0 01-\u00a0 I \u2013 Errada \u2013 s\u00e3o ondas transversais II \u2013 Verdadeira \u2013 vide voc\u00ea deve saber III \u2013 Errada \u2013 ondas sonoras s\u00e3o ondas mec\u00e2nicas R: B 02- B\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 03- E\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 04- E\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 05- D\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 06- D\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 07- D\u00a0\u00a0 \u00a008-\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 09- \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 10- E\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 11- Para<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2401,"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-2405","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2405","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=2405"}],"version-history":[{"count":3,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2405\/revisions"}],"predecessor-version":[{"id":10921,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2405\/revisions\/10921"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2401"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=2405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}