{"id":3999,"date":"2018-06-25T04:54:43","date_gmt":"2018-06-25T04:54:43","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3999"},"modified":"2024-08-22T13:00:55","modified_gmt":"2024-08-22T13:00:55","slug":"dinamica-6-polias-ou-roldanas","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/formulario\/dinamica-6-polias-ou-roldanas\/","title":{"rendered":"Din\u00e2mica 6 – Polias ou Roldanas"},"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 6<\/b><\/span><\/span><\/span><\/p>\n

Polias <\/b><\/span><\/span><\/span>ou Roldanas<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Polias (roldanas)<\/b><\/span><\/span> s\u00e3o\u00a0<\/b><\/span><\/span>dispositivos<\/b><\/span><\/span>\u00a0que t\u00eam por\u00a0<\/b><\/span><\/span>fun\u00e7\u00e3o mudar a dire\u00e7\u00e3o e o sentido\u00a0<\/b><\/span><\/span>(mas <\/b><\/span><\/span>mantendo a intensidade<\/b><\/span><\/span>)\u00a0da\u00a0<\/b><\/span><\/span>for\u00e7a\u00a0que\u00a0traciona <\/b><\/span><\/span>ou tensiona\u00a0\u201cpuxa\u201d um\u00a0<\/b><\/span><\/span>fio\u00a0ou uma\u00a0corda\u00a0<\/b><\/span><\/span>ou podem ser <\/b><\/span><\/span>usadas para\u00a0aumentar ou diminuir a\u00a0intensidade\u00a0de uma\u00a0for\u00e7a. <\/b><\/span><\/span>Podem ser\u00a0<\/b><\/span><\/span>fixas ou m\u00f3veis:<\/b><\/span><\/span><\/span><\/span><\/p>\n

Polia fixa<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Muda a\u00a0<\/b><\/span><\/span>dire\u00e7\u00e3o e sentido<\/b><\/span><\/span>\u00a0de uma\u00a0<\/b><\/span><\/span>for\u00e7a<\/b><\/span><\/span>,\u00a0<\/b><\/span><\/span>mantendo sua intensidade.<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>Est\u00e1 <\/b><\/span><\/span>presa a um suporte r\u00edgido,\u00a0fixo\u00a0<\/b><\/span><\/span>e <\/b><\/span><\/span>executa\u00a0apenas movimento de rota\u00e7\u00e3o, <\/b><\/span><\/span>n\u00e3o de transla\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Exemplos de polia fixa<\/b><\/span><\/span><\/span><\/span><\/p>\n

Na figura 1<\/b><\/span><\/span>, a\u00a0<\/b><\/span><\/span>for\u00e7a aplicada pelo homem<\/b><\/span><\/span>\u00a0sobre a corda que tem\u00a0<\/b><\/span><\/span>dire\u00e7\u00e3o vertical e sentido para baixo <\/b><\/span><\/span>passa a agir sobre o bloco na\u00a0<\/b><\/span><\/span>dire\u00e7\u00e3o horizontal e sentido para a direita<\/b><\/span><\/span>,\u00a0mas com a <\/b><\/span><\/span>mesma intensidade.<\/b><\/span><\/span><\/span><\/span><\/p>\n

<\/p>\n

Na figura 2, <\/b><\/span><\/span>passa de\u00a0vertical e para baixo\u00a0<\/b><\/span><\/span>(aplicada pelo homem sobre a corda)\u00a0para <\/b><\/span><\/span>vertical e para cima\u00a0<\/b><\/span><\/span>(agindo sobre o bloco).\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \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

Na figura 3\u00a0a\u00a0<\/b><\/span><\/span>for\u00e7a aplicada pelo homem\u00a0\u00e9\u00a0transmitida ao bloco como vertical e para cima.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Nas\u00a0<\/b><\/span><\/span>figuras 2 e 3,\u00a0se os\u00a0blocos estiverem em equil\u00edbrio, <\/b><\/span><\/span>a <\/b><\/span><\/span>intensidade da for\u00e7a aplicada \u00e9 sempre igual ao peso do bloco.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Observe<\/b><\/span><\/span> que, em qualquer situa\u00e7\u00e3o, <\/b><\/span><\/span>se o\u00a0homem puxar a corda de 1 metro, cada bloco tamb\u00e9m se deslocar\u00e1 de 1 metro.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\u00a0Polia m\u00f3vel<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

<\/p>\n

Assim, uma\u00a0<\/b><\/span><\/span>polia m\u00f3vel\u00a0consegue\u00a0aumentar ou diminuir a intensidade de for\u00e7as, <\/b><\/span><\/span>mas tem a\u00a0<\/b><\/span><\/span>inconveni\u00eancia de diminuir o deslocamento <\/b><\/span><\/span>do corpo, ou seja, se <\/b><\/span><\/span>sua m\u00e3o subir de 2 metros, o bloco subir\u00e1 metade, apenas 1 metro.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Associa\u00e7\u00e3o de polias<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Uma\u00a0<\/b><\/span><\/span>polia fixa e outra m\u00f3vel<\/b><\/span><\/span><\/span><\/span><\/p>\n

<\/p>\n

Uma\u00a0<\/b><\/span><\/span>polia fixa<\/b><\/span><\/span>\u00a0e\u00a0<\/b><\/span><\/span>v\u00e1rias polias m\u00f3veis<\/b><\/span><\/span>\u00a0(talha exponencial)<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

Formul\u00e1rio completo de F\u00edsica com informa\u00e7\u00f5es \u00fateis (dicas para vestibulares) Din\u00e2mica 6 Polias ou Roldanas Polias (roldanas) s\u00e3o\u00a0dispositivos\u00a0que t\u00eam por\u00a0fun\u00e7\u00e3o mudar a dire\u00e7\u00e3o e o sentido\u00a0(mas mantendo a intensidade)\u00a0da\u00a0for\u00e7a\u00a0que\u00a0traciona ou tensiona\u00a0\u201cpuxa\u201d um\u00a0fio\u00a0ou uma\u00a0corda\u00a0ou podem ser usadas para\u00a0aumentar ou diminuir a\u00a0intensidade\u00a0de uma\u00a0for\u00e7a. Podem ser\u00a0fixas ou m\u00f3veis: Polia fixa Muda a\u00a0dire\u00e7\u00e3o e sentido\u00a0de uma\u00a0for\u00e7a,\u00a0mantendo sua intensidade.\u00a0Est\u00e1 presa a um suporte r\u00edgido,\u00a0fixo\u00a0e executa\u00a0apenas<\/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-3999","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3999","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=3999"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3999\/revisions"}],"predecessor-version":[{"id":4000,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3999\/revisions\/4000"}],"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=3999"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}