{"id":4015,"date":"2018-06-25T05:00:53","date_gmt":"2018-06-25T05:00:53","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=4015"},"modified":"2024-08-22T12:48:19","modified_gmt":"2024-08-22T12:48:19","slug":"dinamica-14-forcas-no-movimento-circular","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/formulario\/dinamica-14-forcas-no-movimento-circular\/","title":{"rendered":"Din\u00e2mica 14 – For\u00e7as no Movimento Circular"},"content":{"rendered":"

Formul\u00e1rio completo de F\u00edsica com informa\u00e7\u00f5es \u00fateis <\/b><\/span><\/span><\/span><\/p>\n

(dicas para vestibulares)<\/b><\/span><\/span><\/span><\/p>\n

Din\u00e2mica 14<\/b><\/span><\/span><\/span><\/p>\n

For\u00e7as no Movimento Circular<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

Informa\u00e7\u00f5es \u00fateis<\/b><\/span><\/span><\/span> <\/b>(Dicas)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Esses <\/b><\/span><\/span><\/span>casos particulares <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>aplica\u00e7\u00f5es<\/b><\/span><\/span><\/span> da <\/b><\/span><\/span><\/span>for\u00e7a resultante centr\u00edpeta <\/b><\/span><\/span><\/span>s\u00e3o muito <\/b><\/span><\/span><\/span>importantes, <\/b><\/span><\/span><\/span>leia-os com aten\u00e7\u00e3o e procure entende-los:<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

Planador ou avi\u00e3o <\/b><\/span><\/span><\/span>inclinado de certo \u00e2ngulo,<\/b><\/span><\/span><\/span> efetuando <\/b><\/span><\/span><\/span>movimento circular <\/b><\/span><\/span><\/span>com velocidade escalar constante V.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

Observe na\u00a0<\/b><\/span><\/span><\/span>express\u00e3o acima<\/b><\/span><\/span><\/span>\u00a0que a\u00a0<\/b><\/span><\/span><\/span>velocidade\u00a0do avi\u00e3o\u00a0depende\u00a0do\u00a0raio R da trajet\u00f3ria<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e do\u00a0<\/b><\/span><\/span><\/span>\u00e2ngulo de\u00a0inclina\u00e7\u00e3o das asas.<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Somente obedecendo \u00e0 essa equa\u00e7\u00e3o <\/b><\/span><\/span><\/span>\u00e9 que o planador\u00a0<\/b><\/span><\/span><\/span>efetuar\u00e1 uma <\/b><\/span><\/span><\/span>curva horizontal<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

<\/p>\n

Carro de\u00a0<\/b><\/span><\/span>massa m<\/b><\/span><\/span>\u00a0passando por uma\u00a0<\/b><\/span><\/span>lombada ou uma depress\u00e3o de raio R com velocidade V.<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

<\/p>\n

Depress\u00e3o<\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

P\u00eandulo C\u00f4nico<\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

Rotor<\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

Globo da morte<\/b><\/span><\/span><\/span><\/p>\n

Suponha um\u00a0<\/b><\/span><\/span><\/span>motociclista de massa total\u00a0m\u00a0(massa dele + massa da moto) <\/b><\/span><\/span><\/span>descrevendo voltas segundo um\u00a0<\/b><\/span><\/span><\/span>plano vertical,<\/b><\/span><\/span><\/span>\u00a0com\u00a0<\/b><\/span><\/span><\/span>velocidade escalar constante\u00a0<\/b><\/span><\/span><\/span>\u00a0no interior de uma esfera met\u00e1lica oca de raio R \u201cglobo da morte\u201d.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

Na express\u00e3o acima\u00a0<\/b><\/span><\/span><\/span>(N = m(g + V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\/R)<\/b><\/span><\/span><\/span>\u00a0verificamos que, como\u00a0<\/b><\/span><\/span><\/span>m, g e R s\u00e3o constantes<\/b><\/span><\/span><\/span>,\u00a0<\/b><\/span><\/span><\/span>N \u00e9 diretamente<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>proporcional a V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

P\u00eandulo simples<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

Consiste em um\u00a0<\/b><\/span><\/span>corpo de massa m<\/b><\/span><\/span>, preso \u00e0 extremidade de um\u00a0<\/b><\/span><\/span>fio<\/b><\/span><\/span>\u00a0de<\/b><\/span><\/span> <\/b>comprimento L<\/b><\/span><\/span>\u00a0oscilando num\u00a0<\/b><\/span><\/span>plano vertical onde os pontos A e C\u00a0 representam os pontos extremos da oscila\u00e7\u00e3o onde\u00a0<\/b><\/span><\/span>o corpo <\/b><\/span><\/span>para retornar, invertendo o sentido de seu movimento.<\/b><\/span><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

Carro<\/b><\/span><\/span><\/span>\u00a0em <\/b><\/span><\/span><\/span>pista sobrelevada<\/b><\/span><\/span><\/span> de\u00a0<\/b><\/span><\/span><\/span>\u00e2ngulo\u00a0\u03b8\u00a0com a horizontal<\/b><\/span><\/span><\/span>,\u00a0<\/b><\/span><\/span><\/span>sem atrito<\/b><\/span><\/span><\/span>\u00a0em pista\u00a0<\/b><\/span><\/span><\/span>circular de raio R, contida num plano horizontal.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

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

<\/p>\n

Gravidade artificial <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>nave pode ser constitu\u00edda<\/b><\/span><\/span><\/span> de modo que <\/b><\/span><\/span><\/span>origine um sistema que forne\u00e7a um ambiente de formato circular que esteja constantemente <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>movimento de rota\u00e7\u00e3o, <\/b><\/span><\/span><\/span>girando com <\/b><\/span><\/span><\/span>velocidade angular constante em torno de um <\/b><\/span><\/span><\/span>ponto (eixo central) <\/b><\/span><\/span><\/span>fixo. <\/b><\/span><\/span><\/span><\/p>\n

Pode ter a <\/b><\/span><\/span><\/span>forma de forma de um cilindro (figura 1), um anel (figura 2) ou outra qualquer <\/b><\/span><\/span><\/span>desde que <\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

constitua uma estrutura<\/b><\/span><\/span><\/span> comprida <\/b><\/span><\/span><\/span>que <\/b><\/span><\/span><\/span>gire em torno de um ponto ou eixo fixo, <\/b><\/span><\/span><\/span>n<\/b><\/span><\/span><\/span>uma r<\/b><\/span><\/span><\/span>ota\u00e7\u00e3o constante,<\/b><\/span><\/span><\/span> de modo a <\/b><\/span><\/span><\/span>simular a gravidade em sua superf\u00edcie interna <\/b><\/span><\/span><\/span>gra\u00e7as \u00e0 <\/b><\/span><\/span><\/span>acelera\u00e7\u00e3o centr\u00edpeta <\/b><\/span><\/span><\/span>gerada por esse <\/b><\/span><\/span><\/span>movimento circular, <\/b><\/span><\/span><\/span>fazendo com que os <\/b><\/span><\/span><\/span>astronautas fiquem de p\u00e9 no ch\u00e3o da nave, como se estivessem na Terra.<\/b><\/span><\/span><\/span><\/p>\n

Essa\u00a0<\/b><\/span><\/span><\/span>simula\u00e7\u00e3o da \u201cgravidade\u201d<\/b><\/span><\/span><\/span> ocorre, pois <\/b><\/span><\/span><\/span>todo corpo em movimento circular tende a se afastar do centro e, no caso, \u201ccolando\u201d nas paredes internas do cilindro (nave).<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

O <\/b><\/span><\/span><\/span>\u201cpeso aparente\u201d do astronauta\u00a0\u00e9 percebido rea\u00e7\u00e3o normal\u00a0<\/b><\/span><\/span><\/span>N<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>das <\/b><\/span><\/span><\/span>paredes da nave sobre ele, <\/b><\/span><\/span><\/span>que \u00e9 a <\/b><\/span><\/span><\/span>pr\u00f3pria for\u00e7a resultante centr\u00edpeta de intensidade N = F<\/b><\/span><\/span><\/span>c<\/b><\/span><\/span><\/sub><\/span>= m.W<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>R, <\/b><\/span><\/span><\/span>que deve ser <\/b><\/span><\/span><\/span>igual ao\u00a0peso P do astronauta na Terra\u00a0onde g = 10m\/s<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

Observe ainda que <\/b><\/span><\/span><\/span>sendo a velocidade angular W de rota\u00e7\u00e3o da nave constante<\/b><\/span><\/span><\/span>, a \u201cgravidade artificial <\/b><\/span><\/span><\/span>g<\/b><\/span><\/span><\/span>\u201d \u00e9 <\/b><\/span><\/span><\/span>diretamente proporcional ao raio R, <\/b><\/span><\/span><\/span>ou seja, <\/b><\/span><\/span><\/span>\u00e0 medida que o tripulante vai se aproximando do centro do sistema rotat\u00f3rio, o raio R vai diminuindo o que provoca tamb\u00e9m uma diminui\u00e7\u00e3o da (gravidade artificial\u201d. <\/b><\/span><\/span><\/span><\/p>\n

Assim, no <\/b><\/span><\/span><\/span>centro do sistema<\/b><\/span><\/span><\/span> a \u201cgravidade artificial <\/b><\/span><\/span><\/span>g\u201d \u00e9 zero <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>a\u00ed<\/b><\/span><\/span><\/span> o tripulante <\/b><\/span><\/span><\/span>flutua.<\/b><\/span><\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Formul\u00e1rio completo de F\u00edsica com informa\u00e7\u00f5es \u00fateis (dicas para vestibulares) Din\u00e2mica 14 For\u00e7as no Movimento Circular Informa\u00e7\u00f5es \u00fateis (Dicas) Esses casos particulares de aplica\u00e7\u00f5es da for\u00e7a resultante centr\u00edpeta s\u00e3o muito importantes, leia-os com aten\u00e7\u00e3o e procure entende-los: Planador ou avi\u00e3o inclinado de certo \u00e2ngulo, efetuando movimento circular com velocidade escalar constante V. Observe na\u00a0express\u00e3o acima\u00a0que a\u00a0velocidade\u00a0do avi\u00e3o\u00a0depende\u00a0do\u00a0raio R da trajet\u00f3ria\u00a0e<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3987,"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-4015","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/4015","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=4015"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/4015\/revisions"}],"predecessor-version":[{"id":4016,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/4015\/revisions\/4016"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3987"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=4015"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}