{"id":746,"date":"2015-05-12T20:26:51","date_gmt":"2015-05-12T20:26:51","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=746"},"modified":"2024-09-02T17:17:17","modified_gmt":"2024-09-02T17:17:17","slug":"resolucao-comentada-acafe-2015","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2015\/exercicios-resolvidos-acafe-2015\/resolucao-comentada-acafe-2015\/","title":{"rendered":"Resolu\u00e7\u00e3o Comentada ACAFE 2015"},"content":{"rendered":"

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

01- <\/span><\/span><\/span>O <\/b><\/span><\/span><\/span>bar\u00f4metro <\/b><\/span><\/span><\/span>\u00e9 um instrumento cuja fun\u00e7\u00e3o \u00e9 <\/b><\/span><\/span><\/span>medir a press\u00e3o atmosf\u00e9rica.<\/b><\/span><\/span><\/span><\/p>\n

Este instrumento foi <\/b><\/span><\/span><\/span>inventado<\/b><\/span><\/span><\/span> em 1643 pelo f\u00edsico e matem\u00e1tico italiano Evangelista <\/b><\/span><\/span><\/span>Torricelli.<\/b><\/span><\/span><\/span><\/p>\n

Existem <\/span><\/span><\/span>dois <\/span><\/span><\/span>tipos de <\/span><\/span><\/span>bar\u00f4metro:<\/span><\/span><\/span> – De <\/b><\/span><\/span><\/span>coluna de merc\u00fario<\/b><\/span><\/span><\/span> – <\/b><\/span><\/span><\/span>Aner\u00f3ide (met\u00e1lico<\/b><\/span><\/span><\/span>).<\/span>\u00a0<\/span><\/span><\/span><\/p>\n

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

02- <\/span><\/span><\/span>Ondas de r\u00e1dio<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>s\u00e3o um tipo de<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>radia\u00e7\u00e3o eletromagn\u00e9tica<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>com<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>comprimento de onda maior (e<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>freq\u00fc\u00eancia<\/b><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span>menor) do que a<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>radia\u00e7\u00e3o infravermelha. Como <\/b><\/span><\/span><\/span>todas as outras ondas eletromagn\u00e9ticas, viajam \u00e0 velocidade da luz, que \u00e9 constante no v\u00e1cuo e de valor aproximado 3,0.10<\/b><\/span><\/span><\/span>5<\/b><\/span><\/span><\/sup><\/span> km\/s. <\/b><\/span><\/span><\/span><\/p>\n

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

03- <\/span><\/span><\/span>(F)<\/b><\/span><\/span><\/span> \"\" A <\/b><\/span><\/span><\/span>quantidade de movimento<\/b><\/span><\/span><\/span> \u00e9 uma <\/b><\/span><\/span><\/span>grandeza vetorial<\/b><\/span><\/span><\/span> e, sua <\/b><\/span><\/span><\/span>dire\u00e7\u00e3o e sentido antes e depois da colis\u00e3o est\u00e3o variando.<\/b><\/span><\/span><\/span><\/p>\n

(V) \"\" Veja anterior.<\/b><\/span><\/span><\/span><\/p>\n

(F) \"\" <\/b><\/span><\/span><\/span>Teorema do impulso: o <\/b><\/span><\/span><\/span>impulso<\/b><\/span><\/span><\/span> de uma for\u00e7a \u00e9 <\/b><\/span><\/span><\/span>igual \u00e0 sua varia\u00e7\u00e3o da quantidade de movimento. <\/b><\/span><\/span><\/span><\/p>\n

(V) \"\" <\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>quantidade de movimento<\/b><\/span><\/span><\/span> da bola imediatamente antes e depois da colis\u00e3o <\/b><\/span><\/span><\/span>variou<\/b><\/span><\/span><\/span>, por\u00e9m, <\/b><\/span><\/span><\/span>sua energia cin\u00e9tica manteve-se constante, pois sua massa e velocidade s\u00e3o constantes e a energia cin\u00e9tica \u00e9 uma grandeza escalar. <\/b><\/span><\/span><\/span><\/p>\n

(V) \"\" <\/b><\/span><\/span><\/span>Teorema do impulso: o <\/b><\/span><\/span><\/span>impulso<\/b><\/span><\/span><\/span> de uma for\u00e7a \u00e9 <\/b><\/span><\/span><\/span>igual \u00e0 sua varia\u00e7\u00e3o da quantidade de movimento. <\/b><\/span><\/span><\/span><\/p>\n

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

04- <\/span><\/span><\/span>A cor <\/b><\/span><\/span><\/span>avermelhada na Lua<\/b><\/span><\/span><\/span> ocorre porque os <\/b><\/span><\/span><\/span>raios de Sol que iluminam o sat\u00e9lite nesta ocasi\u00e3o s\u00e3o<\/b><\/span><\/span><\/span> <\/b>filtrados <\/b><\/span><\/span><\/span>pela atmosfera da Terra sofrendo <\/b><\/span><\/span><\/span>dispers\u00e3o e refra\u00e7\u00e3o<\/b><\/span><\/span><\/span> e chegam \u00e0 mesma com menos luz azul e <\/b><\/span><\/span><\/span>mais vermelha.<\/b><\/span><\/span><\/span><\/p>\n

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

05- <\/span><\/span><\/span>Veja teoria a seguir:<\/b><\/span><\/span><\/span><\/p>\n

Dependendo das posi\u00e7\u00f5es relativas das posi\u00e7\u00f5es ocupadas pela pot\u00eancia (F), apoio (O) e resist\u00eancia (R), as alavancas classificam-se em:<\/b><\/span><\/span><\/span><\/p>\n

\"\"Alavanca interfixa<\/b><\/span><\/span><\/span>\u00a0\u2013 o apoio est\u00e1 entre a for\u00e7a potente e a for\u00e7a resistente<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

Havendo equil\u00edbrio, a soma dos momentos das for\u00e7as em rela\u00e7\u00e3o ao apoio deve ser nula\u00a0 —\u00a0 F<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>.d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>=F<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span>.d<\/b><\/span><\/span><\/span>r\u00ad\u00a0 \u00ad<\/b><\/span><\/span><\/sub><\/span>—\u00a0 F<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span>\/F<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>=d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>\/d<\/b><\/span><\/span><\/span>r\u00ad\u00a0\u00a0<\/b><\/span><\/span><\/sub><\/span>—\u00a0 \u03b7=d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>\/d<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span>\u00a0 —\u00a0 observe que quanto maior for o bra\u00e7o potente, maior ser\u00e1 a vantagem mec\u00e2nica, ou seja, maior ser\u00e1 a for\u00e7a transmitida.<\/b><\/span><\/span><\/span><\/p>\n

Exemplos de alavancas interfixas:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

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

\"\"Alavanca inter-resistente<\/b><\/span><\/span><\/span>\u00a0– a for\u00e7a transmitida (resist\u00eancia)\u00a0\"\"\u00a0localiza-se entre o p\u00f3lo e a for\u00e7a aplicada pelo operador\u00a0\"\".
\n\"\"<\/b><\/span><\/span><\/span><\/p>\n

Havendo equil\u00edbrio a soma dos momentos em rela\u00e7\u00e3o ao p\u00f3lo deve ser nula\u00a0 —\u00a0\u00a0 F<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>.d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>\u00a0+ F<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span>.d<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span>=0\u00a0 —\u00a0<\/b><\/span><\/span><\/span>\u00a0\u03b7=F<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span>\/F<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>=d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>\/d<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span><\/p>\n

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

Quando voc\u00ea est\u00e1 equilibrado na ponta do p\u00e9, os m\u00fasculos g\u00eameos da barriga da perna transmitem a for\u00e7a potente\u00a0\"\",<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

o peso do corpo transmitido pelos ossos t\u00edbia e f\u00edbula corresponde \u00e0 for\u00e7a resistente\u00a0\"\"\u00a0e a ponta do p\u00e9 corresponde ao apoio O.<\/b><\/span><\/span><\/span><\/p>\n

\"\"Alavanca interpotente<\/b><\/span><\/span><\/span>\u00a0– a for\u00e7a aplicada pelo operador\u00a0\"\"\u00a0(pot\u00eancia) localiza-se entre o p\u00f3lo e a for\u00e7a transmitida (resist\u00eancia)\u00a0\"\".<\/b><\/span><\/span><\/span><\/p>\n


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

Havendo equil\u00edbrio\u00a0 —\u00a0 -Fr.dr + Fr.d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>=0\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03b7=Fr\/Fp=d<\/b><\/span><\/span><\/span>p<\/b><\/span><\/span><\/sub><\/span>\/d<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span><\/p>\n

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

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

O antebra\u00e7o corresponde a uma alavanca interpotente. O b\u00edceps \u00e9 um dos m\u00fasculos envolvidos no processo<\/b><\/span><\/span><\/span><\/p>\n

de dobrar nossos bra\u00e7os. Esse m\u00fasculo funciona num sistema de alavanca como \u00e9 mostrado na figura.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u00a0O simples ato de equilibrarmos um objeto na palma da m\u00e3o, estando o bra\u00e7o em posi\u00e7\u00e3o vertical e o antebra\u00e7o em<\/b><\/span><\/span><\/span><\/p>\n

posi\u00e7\u00e3o horizontal, \u00e9 o resultado de um equil\u00edbrio das seguintes for\u00e7as: a for\u00e7a resistente\u00a0\"\"que equilibra o peso do objeto, a for\u00e7a potente\u00a0\"\"\u00a0que o b\u00edceps exerce sobre um dos ossos do antebra\u00e7o e a for\u00e7a que o osso do bra\u00e7o exerce sobre o cotovelo, onde est\u00e1 o p\u00f3lo.<\/b><\/span><\/span><\/span><\/p>\n

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

06- <\/span><\/span><\/span> <\/b>Zero absoluto<\/span><\/span>, ou zero kelvin (0 K) corresponde \u00e0 <\/b><\/span><\/span>temperatura<\/span><\/span>\u00a0<\/b><\/span><\/span>de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>– 273,15 \u00b0C<\/span><\/span>\u00a0<\/b><\/span><\/span>ou<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>– 459.67 \u00b0F<\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

O conceito de zero absoluto foi criado pelo f\u00edsico William Thonsom e ocorre quando um corpo n\u00e3o cont\u00e9m energia alguma, e suas mol\u00e9culas est\u00e3o paradas. O conceito de zero absoluto (0 k) corresponderia \u00e0 temperatura mais baixa existente.<\/b><\/span><\/span><\/span><\/p>\n

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

07- <\/span><\/span><\/span>Forno<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span><\/span>P = U<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R<\/b><\/span><\/span><\/span> \"\" 3125 = 250<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R \"\" R = 62500\/3125 \"\" <\/b><\/span><\/span><\/span>R = 20 \u2126.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Secador de cabelo<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span><\/span>P = U<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R<\/b><\/span><\/span><\/span> \"\" 1210 = 220<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R \"\" R = 48400\/1210 \"\" <\/b><\/span><\/span><\/span>R = 40 \u2126.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Cafeteira<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span><\/span>P = U<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R<\/b><\/span><\/span><\/span> \"\" 550 = 110<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R \"\" R = 12100\/550 \"\" <\/b><\/span><\/span><\/span>R = 22 \u2126.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

L\u00e2mpada de carro<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span><\/span>P = U<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R<\/b><\/span><\/span><\/span> \"\" 36 = 12<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R \"\" R = 144\/36 \"\" <\/b><\/span><\/span><\/span>R = 4 \u2126.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

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

<\/h2>\n

Voltar para exerc\u00edcio.<\/span><\/a><\/h2>\n","protected":false},"excerpt":{"rendered":"

RESOLU\u00c7\u00d5ES 01- O bar\u00f4metro \u00e9 um instrumento cuja fun\u00e7\u00e3o \u00e9 medir a press\u00e3o atmosf\u00e9rica. Este instrumento foi inventado em 1643 pelo f\u00edsico e matem\u00e1tico italiano Evangelista Torricelli. Existem dois tipos de bar\u00f4metro: – De coluna de merc\u00fario – Aner\u00f3ide (met\u00e1lico).\u00a0 R- D 02- Ondas de r\u00e1dio\u00a0s\u00e3o um tipo de\u00a0radia\u00e7\u00e3o eletromagn\u00e9tica\u00a0com\u00a0comprimento de onda maior (e\u00a0freq\u00fc\u00eancia \u00a0menor) do que a\u00a0radia\u00e7\u00e3o infravermelha. Como<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":744,"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-746","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/746","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=746"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/746\/revisions"}],"predecessor-version":[{"id":747,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/746\/revisions\/747"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/744"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=746"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}