{"id":3524,"date":"2018-01-19T03:07:12","date_gmt":"2018-01-19T03:07:12","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3524"},"modified":"2024-09-04T12:33:06","modified_gmt":"2024-09-04T12:33:06","slug":"resolucao-comentada-das-questoes-de-fisica-da-fmj-sp-2018","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2018\/fmj\/resolucao-comentada-das-questoes-de-fisica-da-fmj-sp-2018\/","title":{"rendered":"Resolu\u00e7\u00e3o comentada das quest\u00f5es de F\u00cdSICA da FMJ-SP \u2013 2018"},"content":{"rendered":"

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

FMJ-SP \u2013 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><\/p>\n

\"\"<\/p>\n

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

Sat\u00e9lites geoestacion\u00e1rios\u00a0 ou geosincr\u00f4nicos <\/b><\/span><\/span><\/span><\/span>(sincronizados com o movimento de\u00a0<\/b><\/span><\/span><\/span><\/span>rota\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/span>\u00a0da Terra).<\/b><\/span><\/span><\/span><\/span><\/p>\n

A\u00a0<\/b><\/span><\/span><\/span><\/span>maioria dos sat\u00e9lites de telecomunica\u00e7\u00f5es<\/b><\/span><\/span><\/span><\/span>\u00a0s\u00e3o\u00a0<\/b><\/span><\/span><\/span><\/span>sat\u00e9lites geoestacion\u00e1rios,<\/b><\/span><\/span><\/span><\/span>\u00a0pois se encontram\u00a0<\/b><\/span><\/span><\/span><\/span>parados em rela\u00e7\u00e3o a um ponto fixo sobre a Terra.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Seu\u00a0<\/b><\/span><\/span><\/span><\/span>per\u00edodo T \u00e9 o mesmo que o da Terra (24h)<\/b><\/span><\/span><\/span><\/span>,\u00a0o raio de sua \u00f3rbita \u00e9 de, aproximadamente 36000 km,\u00a0<\/b><\/span><\/span><\/span><\/span>tem a mesma velocidade angular (W) que a Terra<\/b><\/span><\/span><\/span><\/span>\u00a0e se encontram em \u00f3rbitas sobre a linha do equador.\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><\/span><\/p>\n

Acima da altura <\/b><\/span><\/span><\/span>aproximada de 36000 km o <\/b><\/span><\/span><\/span>per\u00edodo do sat\u00e9lite aumenta<\/b><\/span><\/span><\/span> e <\/b><\/span><\/span><\/span>abaixo desse valor, diminui.<\/b><\/span><\/span><\/span><\/p>\n

Sua <\/b><\/span><\/span><\/span>velocidade escalar <\/b><\/span><\/span><\/span>\u00e9 fornecida <\/b><\/span><\/span><\/span>por V = 2\u03c0R\/T<\/b><\/span><\/span><\/span>, que <\/b><\/span><\/span><\/span>n\u00e3o depende de sua m<\/b><\/span><\/span><\/span>assa e que, quanto <\/b><\/span><\/span><\/span>mais afastado da Terra maior ser\u00e1 sua velocidade escalar.<\/b><\/span><\/span><\/span><\/p>\n

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

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

Sempre<\/b><\/span><\/span><\/span> que a colis\u00e3o \u00e9 <\/b><\/span><\/span><\/span>perfeitamente el\u00e1stica <\/b><\/span><\/span><\/span>e os <\/b><\/span><\/span><\/span>corpos possuem a mesma massa, <\/b><\/span><\/span><\/span>eles <\/b><\/span><\/span><\/span>trocam <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

suas velocidades, <\/b><\/span><\/span><\/span>ou seja, se o <\/b><\/span><\/span><\/span>bloco A atinge o B (V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = 0) com velocidade V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>, imediatamente ap\u00f3s a colis\u00e3o, A para (V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>) = 0 e B segue com velocidade V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> = V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

Desprezando os atritos e a resist\u00eancia do ar <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>sistema pode ser considerado conservativo <\/b><\/span><\/span><\/span>(energia<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

mec\u00e2nica = energia cin\u00e9tica + energia potencial gravitacional) e assim o <\/b><\/span><\/span><\/span>bloco B s\u00f3 pararia numa altura H. Como h < H, ele chega at\u00e9 o ponto P.<\/b><\/span><\/span><\/span><\/p>\n

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

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

Pelo gr\u00e1fico, <\/b><\/span><\/span><\/span>quando o cilindro <\/b><\/span><\/span><\/span>est\u00e1 totalmente emerso (no ar) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>for\u00e7a de tra\u00e7\u00e3o <\/b><\/span><\/span><\/span>\u00e9 constante e vale <\/b><\/span><\/span><\/span>T = 120 N, que \u00e9 o pr\u00f3prio peso do cilindro \"\" P = 120 N.<\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>gr\u00e1fico<\/b><\/span><\/span><\/span> tamb\u00e9m <\/b><\/span><\/span><\/span>informa<\/b><\/span><\/span><\/span> que, quando o <\/b><\/span><\/span><\/span>cilindro est\u00e1 totalmente imerso na \u00e1gua <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>for\u00e7a de tra\u00e7\u00e3o <\/b><\/span><\/span><\/span>vale <\/b><\/span><\/span><\/span>T = 40 N <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>nesse caso, al\u00e9m do peso P = 120 N <\/b><\/span><\/span><\/span>(vertical e para baixo) voc\u00ea tem o <\/b><\/span><\/span><\/span>empuxo E <\/b><\/span><\/span><\/span>(vertical e para cima).<\/b><\/span><\/span><\/span><\/p>\n

Intensidade do empuxo<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

\"\"<\/p>\n

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

\"\"<\/p>\n

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

Cargas de mesmo sinal se repelem <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>cargas de sinais opostos se atraem. <\/b><\/span><\/span><\/span><\/p>\n

Veja as <\/b><\/span><\/span><\/span>for\u00e7as que cada carga exerce sobre q<\/b><\/span><\/span><\/span>C<\/b><\/span><\/span><\/sub><\/span>, <\/b><\/span><\/span><\/span>onde <\/b><\/span><\/span><\/span>se quer <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>m\u00f3dulo da for\u00e7a resultante, indicadas <\/b><\/span><\/span><\/span>na <\/b><\/span><\/span><\/span>figura 1.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

C\u00e1lculo do m\u00f3dulo <\/b><\/span><\/span><\/span>(intensidade) de <\/b><\/span><\/span><\/span>cada for\u00e7<\/b><\/span><\/span><\/span>a pela <\/b><\/span><\/span><\/span>lei Coulomb <\/b><\/span><\/span><\/span>cuja <\/b><\/span><\/span><\/span>express\u00e3o matem\u00e1tica <\/b><\/span><\/span><\/span>est\u00e1 <\/b><\/span><\/span><\/span>a seguir:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

Observe que os <\/b><\/span><\/span><\/span>pontos P,Q, R e S <\/b><\/span><\/span><\/span>possuem o <\/b><\/span><\/span><\/span>mesmo potencial<\/b><\/span><\/span><\/span> (curto circuito) ent\u00e3o voc\u00ea <\/b><\/span><\/span><\/span>pode uni-los <\/b><\/span><\/span><\/span>(primeira e segunda figuras) <\/b><\/span><\/span><\/span>refazendo o circuito <\/b><\/span><\/span><\/span>e, calculando a <\/b><\/span><\/span><\/span>resist\u00eancia do resistor equivalente conforme a sequ\u00eancia de figuras. <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/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 FMJ-SP \u2013 2018 01- 02- 03- 04- Sat\u00e9lites geoestacion\u00e1rios\u00a0 ou geosincr\u00f4nicos (sincronizados com o movimento de\u00a0rota\u00e7\u00e3o\u00a0da Terra). A\u00a0maioria dos sat\u00e9lites de telecomunica\u00e7\u00f5es\u00a0s\u00e3o\u00a0sat\u00e9lites geoestacion\u00e1rios,\u00a0pois se encontram\u00a0parados em rela\u00e7\u00e3o a um ponto fixo sobre a Terra. Seu\u00a0per\u00edodo T \u00e9 o mesmo que o da Terra (24h),\u00a0o raio de sua \u00f3rbita \u00e9 de, aproximadamente 36000 km,\u00a0tem<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3522,"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-3524","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3524","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=3524"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3524\/revisions"}],"predecessor-version":[{"id":3525,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3524\/revisions\/3525"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3522"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3524"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}