{"id":3468,"date":"2018-01-19T01:09:20","date_gmt":"2018-01-19T01:09:20","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3468"},"modified":"2024-09-04T12:47:33","modified_gmt":"2024-09-04T12:47:33","slug":"resolucao-comentada-das-questoes-de-fisica-da-unesp-2018","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2018\/unesp\/resolucao-comentada-das-questoes-de-fisica-da-unesp-2018\/","title":{"rendered":"Resolu\u00e7\u00e3o comentada das quest\u00f5es de F\u00cdSICA da UNESP-2018"},"content":{"rendered":"

Resolu\u00e7\u00e3o comentada das quest\u00f5es de F\u00cdSICA da <\/b><\/span><\/span><\/span><\/p>\n

UNESP-2018<\/b><\/span><\/span><\/span><\/p>\n

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

\"\"<\/p>\n

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

\"\"<\/p>\n

03- <\/b><\/span><\/span><\/span>Considerando o <\/b><\/span><\/span><\/span>sistema isolado <\/b><\/span><\/span><\/span>de for\u00e7as externas voc\u00ea pode <\/b><\/span><\/span><\/span>utilizar o princ\u00edpio da conserva\u00e7\u00e3o da quantidade de movimento do sistema imediatamente antes e imediatamente depois da explos\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

Lembre-se que neste ponto <\/b><\/span><\/span><\/span>(altura m\u00e1xima) a velocidade V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> \u00e9 apenas a componente horizontal <\/b><\/span><\/span><\/span>das velocidades vertical e horizontal do lan\u00e7amento obl\u00edquo. Assim ela tem <\/b><\/span><\/span><\/span>m\u00f3dulo V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span>, dire\u00e7\u00e3o horizontal e sentido para a direita.<\/b><\/span><\/span><\/span><\/p>\n

Vamos <\/b><\/span><\/span><\/span>supor que, ap\u00f3s a explos\u00e3o o fragmento A retorne com velocidade V<\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/sub><\/span>(veja figura).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Quantidade de movimento do sistema antes da explos\u00e3o<\/b><\/span><\/span><\/span> \"\"<\/b><\/span><\/span><\/span> <\/b>Q<\/b><\/span><\/span><\/span>sa<\/b><\/span><\/span><\/sub><\/span> = (M<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> + M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>).V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> <\/b>= (2M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> + M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>).V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> \"\"<\/span> Q<\/b><\/span><\/span><\/span>sa<\/b><\/span><\/span><\/sub><\/span> = 3M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Quantidade de movimento do sistema depois da explos\u00e3o<\/b><\/span><\/span><\/span> \"\"<\/b><\/span><\/span><\/span> <\/b>Q<\/b><\/span><\/span><\/span>sd<\/b><\/span><\/span><\/sub><\/span> = M<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>.(-V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>) + M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.(V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>) <\/b><\/span><\/span><\/span>= – 2M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> + M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.(5V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span>) \"\" <\/b><\/span><\/span><\/span>Q<\/b><\/span><\/span><\/span>sd<\/b><\/span><\/span><\/sub><\/span> = – 2M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> + 5M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Q<\/b><\/span><\/span><\/span>sa<\/b><\/span><\/span><\/sub><\/span> = Q<\/b><\/span><\/span><\/span>sd<\/b><\/span><\/span><\/sub><\/span> \"\" 3M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> = – 2M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> + 5M<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> \"\"<\/b><\/span><\/span><\/span> 3V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> \u2013 5V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> = – 2V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> \"\" – 2V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> = – 2V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> \"\" <\/b><\/span><\/span><\/span>V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span> = V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Ent\u00e3o o <\/b><\/span><\/span><\/span>fragmento A retorna com velocidade V<\/b><\/span><\/span><\/span>H<\/b><\/span><\/span><\/sub><\/span> <\/b>possuindo <\/b><\/span><\/span><\/span>trajet\u00f3ria invertida do lan\u00e7amento obl\u00edquo, <\/b><\/span><\/span><\/span>percorrendo o <\/b><\/span><\/span><\/span>mesmo caminho na volta e atingindo o ponto II.<\/b><\/span><\/span><\/span><\/p>\n

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

04- <\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>Taxa de\u00a0<\/b><\/span><\/span><\/span>Metabolismo Basal<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00e9 a <\/b><\/span><\/span><\/span>quantidade m\u00ednima de energia (calorias) <\/b><\/span><\/span><\/span>necess\u00e1ria para <\/b><\/span><\/span><\/span>manter as fun\u00e7\u00f5es vitais do organismo em repouso.<\/b><\/span><\/span><\/span><\/p>\n

(A) Falsa<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

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

Express\u00e3o matem\u00e1tica do n\u00edvel sonoro (NS): <\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Como o <\/b><\/span><\/span><\/span>n\u00edvel sonoro foi fornecido \"\"<\/b><\/span><\/span><\/span> = 60 dB, <\/b><\/span><\/span><\/span>voc\u00ea pode <\/b><\/span><\/span><\/span>descobrir a intensidade do som I <\/b><\/span><\/span><\/span>recebida pelo <\/b><\/span><\/span><\/span>ouvido da pessoa sendo dado I<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span> = 10<\/b><\/span><\/span><\/span>-12<\/b><\/span><\/span><\/sup><\/span> W\/m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

06- <\/b><\/span><\/span><\/span>Prismas dispersivos\u00a0\"\"\u00a0decomp\u00f5em<\/b><\/span><\/span><\/span>\u00a0(dispersam) a\u00a0<\/b><\/span><\/span><\/span>luz policrom\u00e1tica branca\u00a0<\/b><\/span><\/span><\/span>em suas\u00a0<\/b><\/span><\/span><\/span>infinitas<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

componentes monocrom\u00e1ticas (cores) que comp\u00f5em o espectro luminoso.<\/b><\/span><\/span><\/span><\/p>\n

A\u00a0<\/b><\/span><\/span><\/span>dispers\u00e3o luminosa\u00a0<\/b><\/span><\/span><\/span>ocorre <\/b><\/span><\/span><\/span>artificialmente<\/b><\/span><\/span><\/span>\u00a0quando a\u00a0<\/b><\/span><\/span><\/span>luz se dispersa como no interior de um prisma (figura da esquerda) ou passa do ar para a \u00e1gua (figura da direita),\u00a0<\/b><\/span><\/span><\/span>sendo\u00a0<\/b><\/span><\/span><\/span>mais desviada a luz<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

monocrom\u00e1tica violeta\u00a0<\/b><\/span><\/span><\/span>(menor velocidade) e\u00a0<\/b><\/span><\/span><\/span>menos desviada a luz monocrom\u00e1tica vermelha\u00a0<\/b><\/span><\/span><\/span>(maior velocidade).<\/b><\/span><\/span><\/span><\/p>\n

Lembre-se que\u00a0<\/b><\/span><\/span><\/span>essa dispers\u00e3o ocorre com uma\u00a0infinidade\u00a0de cores <\/b><\/span><\/span><\/span>(infinidades de frequ\u00eancias)\u00a0<\/b><\/span><\/span><\/span>que est\u00e3o compreendidas entre o vermelho e o violeta.<\/b><\/span><\/span><\/span><\/p>\n

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

07- <\/b><\/span><\/span><\/span>Representando<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>circuito <\/b><\/span><\/span><\/span>por meio dos <\/b><\/span><\/span><\/span>s\u00edmbolos convencionais:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Como os <\/b><\/span><\/span><\/span>aparelhos de medidas s\u00e3o ideais <\/b><\/span><\/span><\/span>voc\u00ea pode <\/b><\/span><\/span><\/span>\u201ccurto-circuitar\u201d o amper\u00edmetro <\/b><\/span><\/span><\/span>(resist\u00eancia interna nula) e <\/b><\/span><\/span><\/span>retirar o volt\u00edmetro <\/b><\/span><\/span><\/span>(resist\u00eancia interna infinita).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Observe na <\/b><\/span><\/span><\/span>figura acima <\/b><\/span><\/span><\/span>que a <\/b><\/span><\/span><\/span>tens\u00e3o (ddp ou voltagem) no resistor R <\/b><\/span><\/span><\/span>vale <\/b><\/span><\/span><\/span>U<\/b><\/span><\/span><\/span>R<\/b><\/span><\/span><\/sub><\/span> <\/b>= 9,0 \u2013 5,7 <\/b><\/span><\/span><\/span>= 3,3 V <\/b><\/span><\/span><\/span>e que ele <\/b><\/span><\/span><\/span>\u00e9 percorrido por uma corrente el\u00e9trica de i = 0,15 A <\/b><\/span><\/span><\/span>(indica\u00e7\u00e3o do amper\u00edmetro).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

R- E<\/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 das quest\u00f5es de F\u00cdSICA da UNESP-2018 01- 02- 03- Considerando o sistema isolado de for\u00e7as externas voc\u00ea pode utilizar o princ\u00edpio da conserva\u00e7\u00e3o da quantidade de movimento do sistema imediatamente antes e imediatamente depois da explos\u00e3o. Lembre-se que neste ponto (altura m\u00e1xima) a velocidade VH \u00e9 apenas a componente horizontal das velocidades vertical e horizontal do lan\u00e7amento obl\u00edquo.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3466,"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-3468","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3468","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=3468"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3468\/revisions"}],"predecessor-version":[{"id":3470,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3468\/revisions\/3470"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3466"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}