{"id":4093,"date":"2018-07-20T17:56:07","date_gmt":"2018-07-20T17:56:07","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=4093"},"modified":"2024-08-21T17:22:08","modified_gmt":"2024-08-21T17:22:08","slug":"cinematica-14-movimento-circular","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/formulario\/cinematica-14-movimento-circular\/","title":{"rendered":"Cinem\u00e1tica 14 – 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

Cinem\u00e1tica 14<\/b><\/span><\/span><\/span><\/p>\n

MOVIMENTO CIRCULAR<\/b><\/span><\/span><\/span><\/p>\n

Movimento circular Uniforme (MCU)<\/b><\/span><\/span><\/span><\/p>\n

No <\/b><\/span><\/span><\/span>MCU<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>trajet\u00f3ria do corpo <\/b><\/span><\/span><\/span>\u00e9 uma <\/b><\/span><\/span><\/span>circunfer\u00eancia<\/b><\/span><\/span><\/span> e o <\/b><\/span><\/span><\/span>m\u00f3dulo de sua velocidade permanece constante no decorrer do tempo.<\/b><\/span><\/span><\/span><\/p>\n

Conceitos e defini\u00e7\u00f5es<\/b><\/span><\/span><\/span><\/p>\n

Per\u00edodo (T)<\/b><\/span><\/span><\/span> <\/b>de um movimento circular uniforme <\/b><\/span><\/span><\/span>(MCU)<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>definido como sendo o<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>tempo que o<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>m\u00f3vel demora para efetuar uma volta completa (ciclo).<\/b><\/span><\/span><\/span>\u00a0Como o <\/b><\/span><\/span><\/span>MCU \u00e9 um movimento\u00a0<\/b><\/span><\/span><\/span>peri\u00f3dico<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>esse<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>tempo \u00e9 constante<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e representado pela<\/b><\/span><\/span><\/span> <\/b>letra\u00a0(T).<\/b><\/span><\/span><\/span><\/p>\n

Frequ\u00eancia (f)<\/b><\/span><\/span><\/span> <\/b>de um <\/b><\/span><\/span><\/span>MCU<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>definida com sendo o\u00a0<\/b><\/span><\/span><\/span>n\u00famero de voltas completas (ciclos) que um m\u00f3vel ou ponto material efetua na unidade de tempo.<\/b><\/span><\/span><\/span><\/p>\n

Unidades de frequ\u00eancia no SI<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>s\u00e3o normalmente usadas<\/b><\/span><\/span><\/span>:\u00a0<\/b><\/span><\/span><\/span>(voltas)\/s, ou (ciclos)\/s, (oscila\u00e7\u00f5es)\/s ou ainda (vibra\u00e7\u00f5es)\/s, \u00e0s quais denominam-se\u00a0<\/b><\/span><\/span><\/span>hertz, cujo s\u00edmbolo \u00e9\u00a0Hz<\/b><\/span><\/span><\/span>, todas do<\/b><\/span><\/span><\/span>\u00a0sistema internacional de unidades (SI).<\/b><\/span><\/span><\/span><\/p>\n

Utilizam-se tamb\u00e9m\u00a0<\/b><\/span><\/span><\/span>as unidades:<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

Algumas vezes pode\u00a0surgir\u00a0tamb\u00e9m como\u00a0<\/b><\/span><\/span><\/span>unidade de frequ\u00eancia a\u00a0<\/b><\/span><\/span><\/span>rpm (rota\u00e7\u00f5es por minuto),<\/b><\/span><\/span><\/span>\u00a0cuja rela\u00e7\u00e3o com o\u00a0<\/b><\/span><\/span><\/span>Hz (rota\u00e7\u00f5es por segundo)<\/b><\/span><\/span><\/span>\u00a0\u00e9:\u00a0<\/b><\/span><\/span><\/span>1 Hz = 60 rpm.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

Velocidade escalar (V) de um MCU <\/b><\/span><\/span><\/span> <\/b>Para\u00a0qualquer m\u00f3vel em MCU<\/b><\/span><\/span><\/span>, o <\/b><\/span><\/span><\/span>espa\u00e7o percorrido<\/b><\/span><\/span><\/span><\/p>\n

(\u0394S)\u00a0<\/b><\/span><\/span><\/span>durante um\u00a0<\/b><\/span><\/span><\/span>per\u00edodo \u0394t = T<\/b><\/span><\/span><\/span> (tempo que\u00a0demora para efetuar uma volta completa)\u00a0<\/b><\/span><\/span><\/span>ser\u00e1\u00a0\u0394S=2\u03c0R, onde R <\/b><\/span><\/span><\/span>\u00e9 o <\/b><\/span><\/span><\/span>raio da circunfer\u00eancia.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

Velocidade angular (W) de um MCU <\/b><\/span><\/span><\/span> <\/b>observe na <\/b><\/span><\/span><\/span>figura <\/b><\/span><\/span><\/span>que,\u00a0no <\/b><\/span><\/span><\/span>intervalo de tempo\u00a0\u0394t = t \u2013 t<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>,\u00a0<\/b><\/span><\/span><\/span>o\u00a0<\/b><\/span><\/span><\/span>raio\u00a0que\u00a0acompanha\u00a0o m\u00f3vel em seu movimento\u00a0<\/b><\/span><\/span><\/span>descreveu <\/b><\/span><\/span><\/span>\u201cvarreu\u201d um \u00e2ngulo \u0394\u03c6 = \u03c6 \u2013 \u03c6<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

Rela\u00e7\u00e3o entre velocidade escalar (V) e angular (W)<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

Acoplamento de polias e engrenagens<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

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

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

<\/p>\n

<\/p>\n

Os\u00a0<\/b><\/span><\/span><\/span>dois carros A e B\u00a0<\/b><\/span><\/span><\/span>da figura <\/b><\/span><\/span><\/span>mant\u00eam-se\u00a0lado a lado\u00a0numa pista\u00a0circular, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>intervalo de tempo\u00a0\u0394t.<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

<\/p>\n

<\/p>\n

As\u00a0<\/b><\/span><\/span><\/span>bicicletas\u00a0possuem\u00a0coroas dentadas dianteiras\u00a0<\/b><\/span><\/span><\/span>(onde est\u00e3o os pedais)\u00a0<\/b><\/span><\/span><\/span>unidas por uma\u00a0corrente\u00a0\u00e0s\u00a0coroas dentadas traseiras <\/b><\/span><\/span><\/span>(ligadas ao eixo da roda traseira).<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

O\u00a0<\/b><\/span><\/span><\/span>n\u00famero de voltas\u00a0efetuadas pela\u00a0roda traseira <\/b><\/span><\/span><\/span>a\u00a0<\/b><\/span><\/span><\/span>cada pedalada, <\/b><\/span><\/span><\/span>que <\/b><\/span><\/span><\/span>corresponde<\/b><\/span><\/span><\/span> a\u00a0<\/b><\/span><\/span><\/span>uma volta\u00a0completa dos pedais da roda dentada dianteira, <\/b><\/span><\/span><\/span>depende do <\/b><\/span><\/span><\/span>tamanho relativo das coroas <\/b><\/span><\/span><\/span>que est\u00e3o\u00a0<\/b><\/span><\/span><\/span>ligadas pela corrente e obedecem \u00e0 rela\u00e7\u00e3o f<\/b><\/span><\/span><\/span>d<\/b><\/span><\/span><\/sub><\/span>.R<\/b><\/span><\/span><\/span>d<\/b><\/span><\/span><\/sub><\/span>\u00a0= f<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>.R<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Observe que a <\/b><\/span><\/span><\/span>frequ\u00eancia\u00a0da roda dentada\u00a0traseira (f<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>) \u00e9 a mesma que a da roda traseira.<\/b><\/span><\/span><\/span><\/p>\n

Assim, se <\/b><\/span><\/span><\/span>voc\u00ea quiser\u00a0manter <\/b><\/span><\/span><\/span>alta velocidade,<\/b><\/span><\/span><\/span> <\/b>voc\u00ea deve\u00a0<\/b><\/span><\/span><\/span>acionar a coroa dianteira de maior\u00a0raio com a\u00a0coroa traseira de menor raio\u00a0<\/b><\/span><\/span><\/span>e se voc\u00ea quiser fazer\u00a0<\/b><\/span><\/span><\/span>menos esfor\u00e7o numa subida \u00edngreme,<\/b><\/span><\/span><\/span> <\/b>voc\u00ea deve\u00a0<\/b><\/span><\/span><\/span>acionar a coroa dianteira de menor raio com a coroa traseira de maior raio\u00a0<\/b><\/span><\/span><\/span>(veja que nesse caso a velocidade diminui)<\/b><\/span><\/span><\/span><\/p>\n

Fun\u00e7\u00e3o hor\u00e1ria do MCU<\/b><\/span><\/span><\/span><\/p>\n

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

Movimento circular uniformemente variado (MCUV)<\/b><\/span><\/span><\/span><\/p>\n

<\/p>\n

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

Formul\u00e1rio completo de F\u00edsica com informa\u00e7\u00f5es \u00fateis (dicas para vestibulares) Cinem\u00e1tica 14 MOVIMENTO CIRCULAR Movimento circular Uniforme (MCU) No MCU a trajet\u00f3ria do corpo \u00e9 uma circunfer\u00eancia e o m\u00f3dulo de sua velocidade permanece constante no decorrer do tempo. Conceitos e defini\u00e7\u00f5es Per\u00edodo (T) de um movimento circular uniforme (MCU)\u00a0\u00a0definido como sendo o\u00a0tempo que o\u00a0m\u00f3vel demora para efetuar uma volta<\/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-4093","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/4093","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=4093"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/4093\/revisions"}],"predecessor-version":[{"id":4094,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/4093\/revisions\/4094"}],"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=4093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}