{"id":1010,"date":"2015-06-29T02:11:53","date_gmt":"2015-06-29T02:11:53","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=1010"},"modified":"2024-09-02T16:57:32","modified_gmt":"2024-09-02T16:57:32","slug":"resolucao-comentada-da-ufpe-2015","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2015\/exercicios-da-ufpe-2015\/resolucao-comentada-da-ufpe-2015\/","title":{"rendered":"Resolu\u00e7\u00e3o comentada da UFPE 2015"},"content":{"rendered":"

RESOLU\u00c7\u00d5ES DA UFPE-2015<\/span><\/span><\/span><\/p>\n

01- <\/span><\/span><\/span>Se o bloco <\/b><\/span><\/span>cai verticalmente<\/b><\/span><\/span><\/span> e o <\/b><\/span><\/span>m\u00f3dulo de sua velocidade n\u00e3o varia<\/b><\/span><\/span><\/span> <\/b>com o tempo,<\/b><\/span><\/span><\/span> ele est\u00e1 em movimento retil\u00edneo e uniforme) <\/b><\/span><\/span>(MRU<\/b><\/span><\/span><\/span> e, consequentemente em\u00a0<\/b><\/span><\/span>equil\u00edbrio din\u00e2mico<\/b><\/span><\/span><\/span>, cuja<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

conseq\u00fc\u00eancia \u00e9 de que a <\/b><\/span><\/span>for\u00e7a resultante (F<\/b><\/span><\/span><\/span>R<\/b><\/span><\/span><\/sub><\/span>) sobre ele seja nula.<\/b><\/span><\/span><\/span><\/p>\n

Se F<\/b><\/span><\/span>R<\/b><\/span><\/span><\/sub> = 0, o <\/b><\/span><\/span>peso P<\/b><\/span><\/span><\/span> (vertical e para baixo) e a <\/b><\/span><\/span>for\u00e7a de resist\u00eancia<\/b><\/span><\/span><\/span> <\/b>do ar F<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span> <\/b>(vertical e para cima) devem se <\/b><\/span><\/span>anular.<\/b><\/span><\/span><\/span><\/p>\n

P = F<\/b><\/span><\/span>r<\/b><\/span><\/span><\/sub> \"\" do enunciado, P = 100 N e ent\u00e3o <\/b><\/span><\/span>F<\/b><\/span><\/span><\/span>r<\/b><\/span><\/span><\/sub><\/span> = 100 N.<\/b><\/span><\/span><\/span><\/p>\n

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

02- <\/span><\/span><\/span>Quando <\/b><\/span><\/span>t=0<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span>x<\/b><\/span><\/span><\/span> <\/b>= x<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span> = 250 m e V = V<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span> = 10 m\/s.<\/b><\/span><\/span><\/span><\/p>\n

Do gr\u00e1fico \"\" <\/b><\/span><\/span>a = (V \u2013 V<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>)\/(t \u2013 t<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>)<\/b><\/span><\/span><\/span> = (20 \u2013 10)\/(250 \u2013 0) = 10\/250 \"\" <\/b><\/span><\/span>a = 0,04 m\/s<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span>fun\u00e7\u00e3o hor\u00e1ria do espa\u00e7o<\/b><\/span><\/span><\/span> de um MUV \u00e9 \"\" <\/b><\/span><\/span>x(t) = x<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span> + V<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>t + at<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/2<\/b><\/span><\/span><\/span> = 250 + 10t + 0,04t<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sup>\/2\u00a0\"\"<\/b><\/span><\/span><\/p>\n

X(t) = 250 + 10t + 0,02t<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

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

03- <\/span><\/span><\/span>O <\/b><\/span><\/span><\/span>trabalho da for\u00e7a peso<\/b><\/span><\/span><\/span> pode ser calculado pela varia\u00e7\u00e3o da energia potencial gravitacional \"\"<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Do in\u00edcio i para o fim f<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span>W = E<\/b><\/span><\/span><\/span>i<\/b><\/span><\/span><\/sub><\/span>\u00a0\u2013 E<\/b><\/span><\/span><\/span>pf<\/b><\/span><\/span><\/sub><\/span> \"\"\u00a0 W = m.g.h<\/b><\/span><\/span>i<\/b><\/span><\/span><\/sub>\u00a0\u2013 m.g.h<\/b><\/span><\/span>f<\/b><\/span><\/span><\/sub> = m.g.(h<\/b><\/span><\/span>i<\/b><\/span><\/span><\/sub>\u00a0\u2013 h<\/b><\/span><\/span>f<\/b><\/span><\/span><\/sub>).<\/b><\/span><\/span><\/p>\n

W = m.g.(h<\/b><\/span><\/span><\/span>i<\/b><\/span><\/span><\/span><\/sub>\u00a0\u2013 h<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/span><\/sub>) = P(h<\/b><\/span><\/span><\/span>i<\/b><\/span><\/span><\/span><\/sub>\u00a0\u2013 h<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/span><\/sub>) = 600.(0 \u2013 20) \"\" <\/b><\/span><\/span><\/span>W = – 12000 J.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Varia\u00e7\u00e3o <\/b><\/span><\/span><\/span>de energia potencial gravitacional \"\" <\/b><\/span><\/span>\u2206Ep = E<\/b><\/span><\/span><\/span>pf<\/b><\/span><\/span><\/sub><\/span> \u2013 E<\/b><\/span><\/span><\/span>pi<\/b><\/span><\/span><\/sub><\/span> = 12000 \u2013 0 <\/b><\/span><\/span>= 12000 J.<\/b><\/span><\/span><\/span><\/p>\n

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

04- <\/span><\/span><\/span>Em todo processo termodin\u00e2mico c\u00edclico, o estado termodin\u00e2mico final \u00e9 id\u00eantico ao inicial, o que significa que as <\/b><\/span><\/span>temperaturas final e inicial s\u00e3o as mesma, n\u00e3o ocorrendo varia\u00e7\u00e3o de energia interna<\/b><\/span><\/span><\/span><\/p>\n

\"\" \u2206U = 0.<\/b><\/span><\/span><\/span><\/p>\n

W = – 20 J (realizado sobre o g\u00e1s).<\/b><\/span><\/span><\/span><\/p>\n

Segunda lei da termodin\u00e2mica \"\" <\/b><\/span><\/span>\u2206U = Q \u2013 W<\/b><\/span><\/span><\/span> \"\" 0 = Q \u2013 W \"\" Q = W \"\" <\/b><\/span><\/span>Q = – 20 J (Q < 0, cedeu calor para o ambiente).<\/b><\/span><\/span><\/span><\/p>\n

R \u2013 A<\/b><\/span><\/span><\/span><\/p>\n

05- <\/span><\/span><\/span>V = \u03bbf<\/b><\/span><\/span><\/span> \"\" 3.10<\/b><\/span><\/span>8<\/b><\/span><\/span><\/sup> = \u03bb.3.10<\/b><\/span><\/span>17<\/b><\/span><\/span><\/sup> \u03bb = 3.10<\/b><\/span><\/span>8<\/b><\/span><\/span><\/sup>\/3.10<\/b><\/span><\/span>17<\/b><\/span><\/span><\/sup> <\/b>\u03bb <\/b><\/span><\/span><\/span>= 1.10<\/b><\/span><\/span>8 \u2013 17<\/b><\/span><\/span><\/sup> <\/b>= 10<\/b><\/span><\/span><\/span>-9<\/b><\/span><\/span><\/sup><\/span> m.<\/b><\/span><\/span><\/span><\/p>\n

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

06- <\/span><\/span><\/span>Observe na express\u00e3o <\/b><\/span><\/span><\/span>C = Q\/U <\/b><\/span><\/span><\/span>que, como a <\/b><\/span><\/span><\/span>capacidade C \u00e9 a mesma<\/b><\/span><\/span><\/span> (mesmo capacitor), a <\/b><\/span><\/span><\/span>ddp U \u00e9 diretamente proporcional \u00e0 carga Q e, como U \u00e9 quadruplicada a carga Q tamb\u00e9m ser\u00e1 quadruplicada.<\/b><\/span><\/span><\/span><\/p>\n

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

07- <\/span><\/span><\/span>Einstein prop\u00f4s a <\/b><\/span><\/span>quantiza\u00e7\u00e3o da energia<\/b><\/span><\/span><\/span>, ou seja, para ocorr\u00eancia da <\/b><\/span><\/span>eje\u00e7\u00e3o imediata de el\u00e9trons<\/b><\/span><\/span><\/span> da superf\u00edcie, a <\/b><\/span><\/span>energia da radia\u00e7\u00e3o (ondas eletromagn\u00e9ticas)<\/b><\/span><\/span><\/span>estaria <\/b><\/span><\/span>concentrada em pacotes (f\u00f3tons) e<\/b><\/span><\/span><\/span> n\u00e3o distribu\u00edda sobre a onda (previs\u00e3o cl\u00e1ssica). Prop\u00f4s tamb\u00e9m que as <\/b><\/span><\/span>ondas eletromagn\u00e9ticas<\/b><\/span><\/span><\/span> (energia da radia\u00e7\u00e3o) com que os el\u00e9trons s\u00e3o ejetados <\/b><\/span><\/span>n\u00e3o depende da quantidade de f\u00f3tons<\/b><\/span><\/span><\/span> <\/b>emitidos, e sim da frequ\u00eancia<\/b><\/span><\/span><\/span> que esses f\u00f3tons possuem.<\/b><\/span><\/span><\/p>\n

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

 <\/p>\n

Voltar para os Exerc\u00edcios<\/span><\/a><\/h2>\n","protected":false},"excerpt":{"rendered":"

RESOLU\u00c7\u00d5ES DA UFPE-2015 01- Se o bloco cai verticalmente e o m\u00f3dulo de sua velocidade n\u00e3o varia com o tempo, ele est\u00e1 em movimento retil\u00edneo e uniforme) (MRU e, consequentemente em\u00a0equil\u00edbrio din\u00e2mico, cuja conseq\u00fc\u00eancia \u00e9 de que a for\u00e7a resultante (FR) sobre ele seja nula. Se FR = 0, o peso P (vertical e para baixo) e a for\u00e7a de<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1008,"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-1010","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1010","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=1010"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1010\/revisions"}],"predecessor-version":[{"id":1013,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1010\/revisions\/1013"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1008"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=1010"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}