{"id":547,"date":"2015-03-02T03:23:15","date_gmt":"2015-03-02T03:23:15","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=547"},"modified":"2024-09-03T12:50:54","modified_gmt":"2024-09-03T12:50:54","slug":"resolucao-comentada-da-ufscar-2015","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2015\/exercicios-resolvidos-da-ufscar-2015\/resolucao-comentada-da-ufscar-2015\/","title":{"rendered":"Resolu\u00e7\u00e3o comentada da UFSCAR 2015"},"content":{"rendered":"

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

01- <\/b><\/span><\/span><\/span>N\u00e3o existindo atrito <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>sistema \u00e9 conservativo<\/b><\/span><\/span><\/span> e a energia total <\/b><\/span><\/span><\/span>(mec\u00e2nica) \u00e9 constante em qualquer ponto da trajet\u00f3ria.<\/b><\/span><\/span><\/span> Assim, a <\/b><\/span><\/span><\/span>energia potencial gravitacional no ponto mais alto (250 000J)<\/b><\/span><\/span><\/span> tem o <\/b><\/span><\/span><\/span>mesmo valor<\/b><\/span><\/span><\/span> que a <\/b><\/span><\/span><\/span>energia cin\u00e9tica com que ele chega ao solo.<\/b><\/span><\/span><\/span><\/p>\n

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

02- <\/b><\/span><\/span><\/span>Energia renov\u00e1vel<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00e9 aquela que vem de<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>recursos naturais<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>como<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>sol,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>vento<\/b><\/span><\/span><\/span><\/a>,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>chuva<\/b><\/span><\/span><\/span><\/a>,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>mar\u00e9s<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>e<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>energia geot\u00e9rmica<\/b><\/span><\/span><\/span><\/a>, <\/b><\/span><\/span>que s\u00e3o<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>recursos renov\u00e1veis<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>(naturalmente reabastecidos).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Os<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>combust\u00edveis f\u00f3sseis<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>s\u00e3o fontes n\u00e3o-renov\u00e1veis de<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>energia<\/b><\/span><\/span><\/span><\/a>: <\/b><\/span><\/span>n\u00e3o \u00e9 poss\u00edvel repor o que se gasta, uma vez que podem ser necess\u00e1rios milh\u00f5es de anos para poder contar novamente com eles. S\u00e3o<\/b><\/span><\/span><\/span> <\/b>aqueles cujas<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>reservas<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>s\u00e3o limitadas. As principais s\u00e3o a energia<\/b><\/span><\/span><\/span> da<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>fiss\u00e3o nuclear<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>e os<\/b><\/span><\/span><\/span> <\/b>combust\u00edveis f\u00f3sseis<\/b><\/span><\/span><\/span> (<\/b><\/span><\/span>petr\u00f3leo<\/b><\/span><\/span><\/span><\/a>,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>g\u00e1s natural<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>e<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>carv\u00e3o<\/b><\/span><\/span><\/span><\/a>).<\/b><\/span><\/span><\/p>\n

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

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

Convec\u00e7\u00e3o t\u00e9rmica<\/b><\/span><\/span><\/span><\/p>\n

Trata-se da <\/b><\/span><\/span><\/span>transfer\u00eancia<\/b><\/span><\/span><\/span> de energia t\u00e9rmica (calor) pela <\/b><\/span><\/span><\/span>mat\u00e9ria <\/b><\/span><\/span><\/span>em movimento devido \u00e0 diferen\u00e7a de densidades dessa mat\u00e9ria. <\/b><\/span><\/span><\/span>Essa mat\u00e9ria s\u00f3 pode ser fluida (l\u00edquido, g\u00e1s ou vapor). <\/b><\/span><\/span><\/span>Observe a figura abaixo onde se tem tubos de vidro contendo \u00e1gua l\u00edquida.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>\u00e1gua em A, aquecida, expande-se, fica menos densa, mais leve e sobe o trecho AB<\/b><\/span><\/span><\/span>. A <\/b><\/span><\/span><\/span>\u00e1gua mais<\/b><\/span><\/span><\/span> <\/b>fria, mais densa e mais pesada do trecho CD desce e ainda empurra para cima a \u00e1gua quente do<\/b><\/span><\/span><\/span> <\/b>ramo AB<\/b><\/span><\/span><\/span>. Obt\u00e9m-se ent\u00e3o uma circula\u00e7\u00e3o de \u00e1gua na qual a <\/b><\/span><\/span><\/span>transfer\u00eancia de calor<\/b><\/span><\/span><\/span> \u00e9 feita\u00a0 <\/b><\/span><\/span><\/span>atrav\u00e9s da<\/b><\/span><\/span><\/span> <\/b>mat\u00e9ria (no caso, \u00e1gua) e que recebe o nome decorrente de convec\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

Condu\u00e7\u00e3o t\u00e9rmica<\/b><\/span><\/span><\/span><\/p>\n

O calor \u00e9 conduzido de um ponto a outro do corpo <\/b><\/span><\/span><\/span>sem que haja deslocamento das part\u00edculas.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Explicando microscopicamente o fen\u00f4meno: a regi\u00e3o <\/b><\/span><\/span><\/span>pr\u00f3xima da chama<\/b><\/span><\/span><\/span> tem o movimento vibrat\u00f3rio de suas mol\u00e9culas aumentado, adquirindo assim <\/b><\/span><\/span><\/span>maior energia cin\u00e9tica<\/b><\/span><\/span><\/span>, que \u00e9 transferida atrav\u00e9s de choques \u00e0s part\u00edculas vizinhas, que tamb\u00e9m <\/b><\/span><\/span><\/span>aumentam seu movimento vibrat\u00f3rio<\/b><\/span><\/span><\/span>. <\/b><\/span><\/span><\/span>Atrav\u00e9s desse transporte de energia, toda a barra \u00e9 aquecida.<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>condu\u00e7\u00e3o<\/b><\/span><\/span><\/span> n\u00e3o ocorre no v\u00e1cuo, pois ela <\/b><\/span><\/span><\/span>precisa de um meio material para se propagar.<\/b><\/span><\/span><\/span><\/p>\n

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

04- <\/b><\/span><\/span><\/span>Em<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>astronomia<\/a>, chama-se<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>superlua<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>ou<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>superlua cheia<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>a ocasi\u00e3o<\/b><\/span><\/span><\/span> na qual a<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>lua cheia<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>se situa a n\u00e3o mais de 10% do seu ponto <\/b><\/span><\/span><\/span>mais pr\u00f3ximo da<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Terra<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>no percurso da sua<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00f3rbita<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>(o<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>perigeu<\/a>).<\/b><\/span><\/span><\/span> Isto<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

acontece devido \u00e0 \u00f3rbita lunar ser<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>el\u00edptica<\/b><\/span><\/span><\/span><\/a>\u00a0<\/b><\/span><\/span><\/span>e o seu centro n\u00e3o coincidir com o centro da Terra. Nos referidos casos, por estar <\/b><\/span><\/span><\/span>mais pr\u00f3xima da Terra e com a Terra entre a Lua e o Sol, apresenta-se maior e mais brilhante que o normal.<\/b><\/span><\/span><\/span><\/p>\n

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

05- <\/b><\/span><\/span><\/span>Como o corpo p\u00e1ssaro possui resist\u00eancia el\u00e9trica e <\/b><\/span><\/span><\/span>seus p\u00e9s est\u00e3o bem pr\u00f3ximos<\/b><\/span><\/span><\/span>, a ddp <\/b><\/span><\/span><\/span>(diferen\u00e7a de potencial) produzida entre seus \u00e9s \u00e9 baixa<\/b><\/span><\/span><\/span> e a corrente el\u00e9trica seguir\u00e1 pelo fio, <\/b><\/span><\/span><\/span>n\u00e3o passando por ele, n\u00e3o o eletrocutando<\/b><\/span><\/span><\/span>.<\/span><\/span><\/span><\/p>\n

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

Voltar para os Exerc\u00edcios<\/span><\/a><\/h3>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

RESOLU\u00c7\u00d5ES 01- N\u00e3o existindo atrito o sistema \u00e9 conservativo e a energia total (mec\u00e2nica) \u00e9 constante em qualquer ponto da trajet\u00f3ria. Assim, a energia potencial gravitacional no ponto mais alto (250 000J) tem o mesmo valor que a energia cin\u00e9tica com que ele chega ao solo. R- C 02- Energia renov\u00e1vel\u00a0\u00e9 aquela que vem de\u00a0recursos naturais\u00a0como\u00a0sol,\u00a0vento,\u00a0chuva,\u00a0mar\u00e9s\u00a0e\u00a0energia geot\u00e9rmica, que s\u00e3o\u00a0recursos renov\u00e1veis\u00a0(naturalmente<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":545,"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-547","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/547","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=547"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/547\/revisions"}],"predecessor-version":[{"id":10997,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/547\/revisions\/10997"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/545"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=547"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}