{"id":2535,"date":"2016-10-18T22:28:33","date_gmt":"2016-10-18T22:28:33","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=2535"},"modified":"2024-09-02T15:17:05","modified_gmt":"2024-09-02T15:17:05","slug":"movimento-circular-uniforme-mcu","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/raciocinio-logico\/movimento-circular-uniforme-mcu\/","title":{"rendered":"MOVIMENTO CIRCULAR UNIFORME (MCU)"},"content":{"rendered":"

MOVIMENTO CIRCULAR UNIFORME (MCU)<\/b><\/span><\/span><\/span><\/p>\n

FORMUL\u00c1RIO<\/b><\/span><\/span><\/span><\/p>\n

\"\" Per\u00edodo e frequ\u00eancia<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\" Velocidade escalar (linear) V de um MCU<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\" Velocidade angular (W) de um MCU<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

\"\"<\/p>\n

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

\"\"<\/p>\n

Exerc\u00edcios de vestibulares com resolu\u00e7\u00f5es comentadas sobre<\/b><\/span><\/span><\/span><\/p>\n

Movimento Circular Uniforme<\/b><\/span><\/span><\/span><\/p>\n

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

01-(UNESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Quem <\/b><\/span><\/span><\/span>est\u00e1 na Terra v\u00ea sempre a mesma face da lua. Isto ocorre <\/b><\/span><\/span><\/span>porque:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>Lua n\u00e3o<\/b><\/span><\/span><\/span> efetua <\/b><\/span><\/span><\/span>rota\u00e7\u00e3o e nem transla\u00e7\u00e3o.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>Lua n\u00e3o<\/b><\/span><\/span><\/span> efetua <\/b><\/span><\/span><\/span>rota\u00e7\u00e3o, apenas transla\u00e7\u00e3o.
\nc) <\/b><\/span><\/span><\/span>os <\/b><\/span><\/span><\/span>per\u00edodos de rota\u00e7\u00e3o e transla\u00e7\u00e3o da Lua s\u00e3o iguais.\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>oportunidades<\/b><\/span><\/span><\/span> para se <\/b><\/span><\/span><\/span>observar a face oculta coincidem com o per\u00edodo diurno da Terra.<\/b><\/span><\/span><\/span>
\n<\/b><\/span><\/span><\/span>e) <\/b><\/span><\/span><\/span>enquanto a <\/b><\/span><\/span><\/span>Lua d\u00e1 uma volta em torno da Terra, esta d\u00e1 uma volta em torno do seu eixo.<\/b><\/span><\/span><\/span><\/p>\n

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

02-(UFSM-RS)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>trator tem as rodas traseiras maiores <\/b><\/span><\/span><\/span>do que as <\/b><\/span><\/span><\/span>dianteiras e desloca-se<\/b><\/span><\/span><\/span> com <\/b><\/span><\/span><\/span>velocidade constante.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Pode-se <\/b><\/span><\/span><\/span>afirmar que, do ponto de vista do tratorista, <\/b><\/span><\/span><\/span>os <\/b><\/span><\/span><\/span>m\u00f3dulos das velocidades lineares <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>qualquer ponto das bandas de rodagem das rodas da frente (v<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>) e de tr\u00e1s (v<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>) <\/b><\/span><\/span><\/span>e os <\/b><\/span><\/span><\/span>m\u00f3dulos das velocidades angulares das rodas da frente (W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>) e de tr\u00e1s (W<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>) s\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>v<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0> v<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0e W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0> W<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>v<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0> v<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0e W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0< W<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>v<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0< v<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0e W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0= W<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>v<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0= v<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0e W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0> W<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>v<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0= v<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span>\u00a0e W<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/sub><\/span>\u00a0= W<\/b><\/span><\/span><\/span>t<\/b><\/span><\/span><\/sub><\/span><\/p>\n

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

03-(UNIFESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

M\u00e3e e filho <\/b><\/span><\/span><\/span>passeiam de <\/b><\/span><\/span><\/span>bicicleta e andam lado a lado com a mesma velocidade.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Sabe-se que o <\/b><\/span><\/span><\/span>di\u00e2metro das rodas da bicicleta da m\u00e3e <\/b><\/span><\/span><\/span>\u00e9 o <\/b><\/span><\/span><\/span>dobro do di\u00e2metro das rodas da bicicleta do filho.<\/b><\/span><\/span><\/span> Pode-se <\/b><\/span><\/span><\/span>afirmar que as rodas da bicicleta da m\u00e3e giram com<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>metade da freq\u00fc\u00eancia e da velocidade angular <\/b><\/span><\/span><\/span>com que <\/b><\/span><\/span><\/span>giram as rodas da bicicleta do filho.<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>mesma freq\u00fc\u00eancia e velocidade angular <\/b><\/span><\/span><\/span>com que <\/b><\/span><\/span><\/span>giram as rodas da bicicleta do filho.<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>dobro da freq\u00fc\u00eancia e da velocidade angular<\/b><\/span><\/span><\/span> com <\/b><\/span><\/span><\/span>que giram as rodas da bicicleta do filho.<\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>mesma freq\u00fc\u00eancia das rodas da bicicleta do filho,<\/b><\/span><\/span><\/span> mas com <\/b><\/span><\/span><\/span>metade da velocidade angular.<\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>mesma freq\u00fc\u00eancia das rodas da bicicleta do filho,<\/b><\/span><\/span><\/span> mas com <\/b><\/span><\/span><\/span>o dobro da velocidade angular.<\/b><\/span><\/span><\/span><\/p>\n

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

04-(UNICAMP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>quadro (a), abaixo, <\/b><\/span><\/span><\/span>refere-se <\/b><\/span><\/span><\/span>\u00e0 imagem de televis\u00e3o de um carro parado, <\/b><\/span><\/span><\/span>em que podemos <\/b><\/span><\/span><\/span>distinguir claramente <\/b><\/span><\/span><\/span>a<\/b><\/span><\/span><\/span>\"\"<\/p>\n

marca do pneu (“PNU”). <\/b><\/span><\/span><\/span><\/p>\n

Quando <\/b><\/span><\/span><\/span>o carro est\u00e1 em movimento, a imagem da marca aparece<\/b><\/span><\/span><\/span> como um <\/b><\/span><\/span><\/span>borr\u00e3o em volta de toda a roda, como ilustrado em (b).<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>marca do pneu volta a ser n\u00edtida, <\/b><\/span><\/span><\/span>mesmo com o <\/b><\/span><\/span><\/span>carro em movimento, <\/b><\/span><\/span><\/span>quando <\/b><\/span><\/span><\/span>este atinge uma determinada velocidade. <\/b><\/span><\/span><\/span><\/p>\n

Essa <\/b><\/span><\/span><\/span>ilus\u00e3o de movimento <\/b><\/span><\/span><\/span>na <\/b><\/span><\/span><\/span>imagem gravada \u00e9 devido \u00e0 freq\u00fc\u00eancia de grava\u00e7\u00e3o de 30 quadros por<\/b><\/span><\/span><\/span> <\/b>segundo (30 Hz). <\/b><\/span><\/span><\/span><\/p>\n

Considerando que o <\/b><\/span><\/span><\/span>di\u00e2metro do pneu \u00e9 igual a 0,6 m e \u03c0 = 3,0, <\/b><\/span><\/span><\/span>responda:<\/b><\/span><\/span><\/span><\/p>\n

a) Quantas voltas <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>pneu completa em um segundo, <\/b><\/span><\/span><\/span>quando a <\/b><\/span><\/span><\/span>marca filmada pela c\u00e2mara aparece parada na imagem, mesmo estando o carro em movimento?<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>Qual a <\/b><\/span><\/span><\/span>menor freq\u00fc\u00eancia angular W do pneu em movimento, <\/b><\/span><\/span><\/span>quando a <\/b><\/span><\/span><\/span>marca aparece parada?<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>Qual a <\/b><\/span><\/span><\/span>menor velocidade linear <\/b><\/span><\/span><\/span>(em m\/s) que o <\/b><\/span><\/span><\/span>carro pode ter na figura (c)?<\/b><\/span><\/span><\/span><\/p>\n

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

05-(UFJF-MG)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um veloc\u00edmetro comum de carro mede, <\/b><\/span><\/span><\/span>na realidade, a <\/b><\/span><\/span><\/span>velocidade angular do eixo da roda,<\/b><\/span><\/span><\/span> e indica <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

um <\/b><\/span><\/span><\/span>valor que<\/b><\/span><\/span><\/span> <\/b>corresponde \u00e0 velocidade do carro.<\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>veloc\u00edmetro <\/b><\/span><\/span><\/span>para um determinado carro sai da f\u00e1brica <\/b><\/span><\/span><\/span>calibrado para uma roda de 20 polegadas <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>di\u00e2metro (isso inclui o pneu).<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Um <\/b><\/span><\/span><\/span>motorista resolve trocar as rodas do carro para 22 polegadas de di\u00e2metro. <\/b><\/span><\/span><\/span>Assim, <\/b><\/span><\/span><\/span>quando<\/b><\/span><\/span><\/span> o <\/b><\/span><\/span><\/span>veloc\u00edmetro indica 100km\/h,<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>velocidade real <\/b><\/span><\/span><\/span>do carro \u00e9:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

06-(FUVEST-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>figura ilustra uma roda d\u2019agua constitu\u00edda de 16 cubas. <\/b><\/span><\/span><\/span><\/p>\n

Cada cuba <\/b><\/span><\/span><\/span>recebe <\/b><\/span><\/span><\/span>5L de \u00e1gua de uma bica cuja vaz\u00e3o \u00e9 160L\/min. <\/b><\/span><\/span><\/span>A roda gira em <\/b><\/span><\/span><\/span>movimento uniforme.<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>Qual \u00e9 o <\/b><\/span><\/span><\/span>per\u00edodo de rota\u00e7\u00e3o da roda?<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>Qual \u00e9 a <\/b><\/span><\/span><\/span>quantidade de \u00e1gua utilizada em 1 hora de funcionamento do sistema?<\/b><\/span><\/span><\/span><\/p>\n

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

07-(FUVEST-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>Esta\u00e7\u00e3o Espacial Internacional mant\u00e9m <\/b><\/span><\/span><\/span>atualmente uma <\/b><\/span><\/span><\/span>\u00f3rbita circular em torno da Terra, <\/b><\/span><\/span><\/span>de tal forma que <\/b><\/span><\/span><\/span>permanece sempre em um plano, normal a uma dire\u00e7\u00e3o fixa no espa\u00e7o. <\/b><\/span><\/span><\/span><\/p>\n

Esse <\/b><\/span><\/span><\/span>plano cont\u00e9m o centro da Terra e faz um \u00e2ngulo de 40\u00b0 com o eixo de rota\u00e7\u00e3o da Terra. <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Em um <\/b><\/span><\/span><\/span>certo momento, a Esta\u00e7\u00e3o passa sobre Macap\u00e1, <\/b><\/span><\/span><\/span>que se encontra na <\/b><\/span><\/span><\/span>linha do Equador. <\/b><\/span><\/span><\/span><\/p>\n

Depois de uma volta completa em sua \u00f3rbita, <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>Esta\u00e7\u00e3o passar\u00e1 <\/b><\/span><\/span><\/span>novamente sobre <\/b><\/span><\/span><\/span>o Equador em um ponto que est\u00e1 a uma dist\u00e2ncia de Macap\u00e1 de, <\/b><\/span><\/span><\/span>aproximadamente,<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

08-(UFU-MG)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>rel\u00f3gio com mecanismo defeituoso atrasa 10 minutos a cada hora. <\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>velocidade angular m\u00e9dia <\/b><\/span><\/span><\/span>do <\/b><\/span><\/span><\/span>ponteiro maior<\/b><\/span><\/span><\/span> <\/b>desse rel\u00f3gio,<\/b><\/span><\/span><\/span> quando <\/b><\/span><\/span><\/span>calculada com o uso de um rel\u00f3gio sem defeitos, <\/b><\/span><\/span><\/span>vale, em <\/b><\/span><\/span><\/span>rad\/s,<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span><\/span>\u03c0<\/b><\/span><\/span><\/span>\/2160\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

b) <\/b><\/span><\/span><\/span><\/span>\u03c0<\/b><\/span><\/span><\/span> \/2100\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

c) <\/b><\/span><\/span><\/span><\/span>\u03c0<\/b><\/span><\/span><\/span> \/3600\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

d) <\/b><\/span><\/span><\/span><\/span>\u03c0<\/b><\/span><\/span><\/span> \/1500<\/b><\/span><\/span><\/span><\/span><\/p>\n

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

09-(UNESP-SP)<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Sat\u00e9lites de \u00f3rbita polar <\/b><\/span><\/span><\/span>giram numa <\/b><\/span><\/span><\/span>\u00f3rbita que passa sobre os p\u00f3los terrestres <\/b><\/span><\/span><\/span>e que <\/b><\/span><\/span><\/span>permanece sempre em um plano fixo em rela\u00e7\u00e3o \u00e0s estrelas.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Pesquisadores de <\/b><\/span><\/span><\/span>esta\u00e7\u00f5es oceanogr\u00e1ficas, preocupados com os efeitos do aquecimento global, utilizam sat\u00e9lites desse tipo para detectar <\/b><\/span><\/span><\/span>regularmente <\/b><\/span><\/span><\/span>pequenas varia\u00e7\u00f5es de temperatura <\/b><\/span><\/span><\/span>e medir o <\/b><\/span><\/span><\/span>espectro da radia\u00e7\u00e3o t\u00e9rmica de diferentes regi\u00f5es do planeta.<\/b><\/span><\/span><\/span><\/p>\n

Considere o sat\u00e9lite a <\/b><\/span><\/span><\/span>5298 km acima da superf\u00edcie da Terra, <\/b><\/span><\/span><\/span>deslocando-se com <\/b><\/span><\/span><\/span>velocidade de 5849 m\/s em uma \u00f3rbita circular. <\/b><\/span><\/span><\/span><\/p>\n

Estime quantas passagens o sat\u00e9lite far\u00e1 pela linha do equador em cada per\u00edodo de 24 horas.<\/b><\/span><\/span><\/span><\/p>\n

Utilize a <\/b><\/span><\/span><\/span>aproxima\u00e7\u00e3o \u03c0 = 3,0 e suponha a Terra esf\u00e9rica, com raio de 6400 km.<\/b><\/span><\/span><\/span><\/p>\n

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

10-(UNESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>cilindro oco de 3,0 m de comprimento, <\/b><\/span><\/span><\/span>cujas <\/b><\/span><\/span><\/span>bases s\u00e3o tampadas com papel fino,<\/b><\/span><\/span><\/span> <\/b>gira <\/b><\/span><\/span><\/span>rapidamente <\/b><\/span><\/span><\/span>em torno de seu eixo com velocidade angular constante. <\/b><\/span><\/span><\/span>\"\"<\/p>\n

Uma <\/b><\/span><\/span><\/span>bala disparada com velocidade de 600 m\/s, paralelamente ao eixo do cilindro<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>perfura <\/b><\/span><\/span><\/span>suas <\/b><\/span><\/span><\/span>bases em dois pontos,<\/b><\/span><\/span><\/span> <\/b>P<\/b><\/span><\/span><\/span> na primeira <\/b><\/span><\/span><\/span>base<\/b><\/span><\/span><\/span> e <\/b><\/span><\/span><\/span>Q<\/b><\/span><\/span><\/span> na <\/b><\/span><\/span><\/span>segunda. <\/b><\/span><\/span><\/span><\/p>\n

Os <\/b><\/span><\/span><\/span>efeitos da gravidade e da resist\u00eancia do ar <\/b><\/span><\/span><\/span>podem <\/b><\/span><\/span><\/span>ser desprezados.<\/b><\/span><\/span><\/span><\/p>\n

a) Quanto tempo <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>bala <\/b><\/span><\/span><\/span>levou para <\/b><\/span><\/span><\/span>atravessar o cilindro?<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>Examinando as <\/b><\/span><\/span><\/span>duas bases de papel<\/b><\/span><\/span><\/span>, verifica-se que <\/b><\/span><\/span><\/span>entre P e Q h\u00e1 um deslocamento angular <\/b><\/span><\/span><\/span>de <\/b><\/span><\/span><\/span>9\u00b0. <\/b><\/span><\/span><\/span><\/p>\n

Qual \u00e9 a <\/b><\/span><\/span><\/span>freq\u00fc\u00eancia de rota\u00e7\u00e3o do cilindro, em hertz, <\/b><\/span><\/span><\/span>sabendo que <\/b><\/span><\/span><\/span>n\u00e3o houve mais do que uma rota\u00e7\u00e3o do cilindro durante o tempo que a bala levou para atravess\u00e1-lo?<\/b><\/span><\/span><\/span><\/p>\n

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

11-(UNESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

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

Um disco horizontal, de raio R = 0,50m, gira em torno de seu eixo <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>velocidade angular W = 2\u03c0<\/b><\/span><\/span><\/span><\/p>\n

rad\/s.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>proj\u00e9til \u00e9 lan\u00e7ado de fora <\/b><\/span><\/span><\/span>no mesmo <\/b><\/span><\/span><\/span>plano do disco <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>rasante a ele, sem toc\u00e1-lo, <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>velocidade V<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>\u00a0(figura), <\/b><\/span><\/span><\/span>passando sobre o ponto P.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

O <\/b><\/span><\/span><\/span>proj\u00e9til sai do disco<\/b><\/span><\/span><\/span> pelo <\/b><\/span><\/span><\/span>ponto Q, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>instante\u00a0 em que o ponto P est\u00e1 passando por a\u00ed <\/b><\/span><\/span><\/span>pela <\/b><\/span><\/span><\/span>primeira vez. Qual \u00e9 a velocidade V<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>?<\/b><\/span><\/span><\/span><\/p>\n

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

12-(UNIFESP-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Tr\u00eas corpos <\/b><\/span><\/span><\/span>est\u00e3o em <\/b><\/span><\/span><\/span>repouso em rela\u00e7\u00e3o ao solo, <\/b><\/span><\/span><\/span>situados em <\/b><\/span><\/span><\/span>tr\u00eas cidades: Macap\u00e1, <\/b><\/span><\/span><\/span>localizada na <\/b><\/span><\/span><\/span>linha do Equador, S\u00e3o Paulo, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>tr\u00f3pico de Capric\u00f3rnio<\/b><\/span><\/span><\/span>, e <\/b><\/span><\/span><\/span>Salekhard, na R\u00fassia, <\/b><\/span><\/span><\/span>localizada no <\/b><\/span><\/span><\/span>c\u00edrculo Polar \u00c1rtico.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Pode-se afirmar <\/b><\/span><\/span><\/span>que <\/b><\/span><\/span><\/span>esses tr\u00eas corpos giram em torno do eixo da Terra <\/b><\/span><\/span><\/span>descrevendo <\/b><\/span><\/span><\/span>movimentos circulares uniformes<\/b><\/span><\/span><\/span>, com<\/b><\/span><\/span><\/span><\/p>\n

A) <\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>mesmas freq\u00fc\u00eancia e velocidade angular,<\/b><\/span><\/span><\/span> mas o corpo <\/b><\/span><\/span><\/span>localizado em Macap\u00e1 tem a maior velocidade tangencial.<\/b><\/span><\/span><\/span><\/p>\n

B) <\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>mesmas freq\u00fc\u00eancia e velocidade angular, <\/b><\/span><\/span><\/span>mas o corpo <\/b><\/span><\/span><\/span>localizado em S\u00e3o Paulo tem a maior velocidade tangencial.<\/b><\/span><\/span><\/span><\/p>\n

C) <\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>mesmas freq\u00fc\u00eancia e velocidade angular, <\/b><\/span><\/span><\/span>mas o corpo <\/b><\/span><\/span><\/span>localizado em Selekhard tem a maior velocidade tangencial.<\/b><\/span><\/span><\/span><\/p>\n

D) <\/b><\/span><\/span><\/span>as <\/b><\/span><\/span><\/span>mesmas freq\u00fc\u00eancia, velocidade angular e velocidade tangencial, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>qualquer cidade.<\/b><\/span><\/span><\/span><\/p>\n

E) freq\u00fc\u00eancia, velocidade angular e velocidade tangencial diferentes <\/b><\/span><\/span><\/span>entre si, <\/b><\/span><\/span><\/span>em cada cidade.<\/b><\/span><\/span><\/span><\/p>\n

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

13-(FATEC-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

As <\/b><\/span><\/span><\/span>rodas dentadas A, B e C t\u00eam, respectivamente, 32, 64 e 96 dentes, <\/b><\/span><\/span><\/span>como mostra a figura.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Sabendo que <\/b><\/span><\/span><\/span>C, de raio 12cm, <\/b><\/span><\/span><\/span>tem <\/b><\/span><\/span><\/span>velocidade angular de 6 rad\/s,<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>velocidade linear <\/b><\/span><\/span><\/span>de um <\/b><\/span><\/span><\/span>ponto<\/b><\/span><\/span><\/span> da <\/b><\/span><\/span><\/span>periferia da roda B <\/b><\/span><\/span><\/span>e a <\/b><\/span><\/span><\/span>velocidade angular da roda A s\u00e3o, <\/b><\/span><\/span><\/span>respectivamente:<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>72 cm\/s e 9,0 rad\/s\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>36 cm\/s e 9,0 rad\/s\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>72 cm\/s e 18 rad\/s\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>36 cm\/s e 18 rad\/s\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>18 cm\/s e 36 rad\/s<\/b><\/span><\/span><\/span><\/p>\n

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

14-(UFJF-MG)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

No ato de <\/b><\/span><\/span><\/span>manobrar seu carro para estacionar, <\/b><\/span><\/span><\/span>uma motorista <\/b><\/span><\/span><\/span>deixa um dos pneus raspar <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>meio fio. <\/b><\/span><\/span><\/span>Com isso, <\/b><\/span><\/span><\/span>uma<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

pequena mancha branca fica no pneu. <\/b><\/span><\/span><\/span><\/p>\n

\u00c0 noite,<\/b><\/span><\/span><\/span> o carro est\u00e1 <\/b><\/span><\/span><\/span>passando em frente a uma casa noturna iluminada por uma l\u00e2mpada estrobosc\u00f3pica<\/b><\/span><\/span><\/span> com <\/b><\/span><\/span><\/span>freq\u00fc\u00eancia de 5Hz. <\/b><\/span><\/span><\/span><\/p>\n

Nessa situa\u00e7\u00e3o, <\/b><\/span><\/span><\/span>uma pessoa olha <\/b><\/span><\/span><\/span>e tem a <\/b><\/span><\/span><\/span>impress\u00e3o de que o pneu com a mancha branca est\u00e1 <\/b><\/span><\/span><\/span>girando <\/b><\/span><\/span><\/span>como se o carro estivesse se movendo para tr\u00e1s<\/b><\/span><\/span><\/span>, embora ele <\/b><\/span><\/span><\/span>esteja deslocando-se para frente.<\/b><\/span><\/span><\/span><\/p>\n

Uma <\/b><\/span><\/span><\/span>poss\u00edvel raz\u00e3o para isto <\/b><\/span><\/span><\/span>\u00e9 que a <\/b><\/span><\/span><\/span>freq\u00fc\u00eancia de rota\u00e7\u00e3o do pneu <\/b><\/span><\/span><\/span>\u00e9<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>maior que <\/b><\/span><\/span><\/span>5 Hz <\/b><\/span><\/span><\/span>e menor que <\/b><\/span><\/span><\/span>6 Hz.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>maior que <\/b><\/span><\/span><\/span>4 Hz <\/b><\/span><\/span><\/span>e menor que <\/b><\/span><\/span><\/span>5 Hz.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>exatamente igual a <\/b><\/span><\/span><\/span>5 Hz.<\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>maior que <\/b><\/span><\/span><\/span>10 Hz <\/b><\/span><\/span><\/span>e menor que <\/b><\/span><\/span><\/span>11 Hz.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>certamente maior que <\/b><\/span><\/span><\/span>5 Hz.<\/b><\/span><\/span><\/span><\/p>\n

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

15-(UFRJ-RJ)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>olho humano ret\u00e9m durante 1\/24 de segundo as imagens que se formam na retina.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Essa <\/b><\/span><\/span><\/span>mem\u00f3ria visual permitiu a inven\u00e7\u00e3o do cinema. <\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>filmadora bate 24 fotografias <\/b><\/span><\/span><\/span>(fotogramas) <\/b><\/span><\/span><\/span>por<\/b><\/span><\/span><\/span> <\/b>segundo.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Uma vez <\/b><\/span><\/span><\/span>revelado,<\/b><\/span><\/span><\/span> o filme \u00e9 <\/b><\/span><\/span><\/span>projetado \u00e0 raz\u00e3o de 24 fotogramas por segundo. <\/b><\/span><\/span><\/span>Assim, o <\/b><\/span><\/span><\/span>fotograma seguinte \u00e9 projetado no exato instante<\/b><\/span><\/span><\/span> em que o <\/b><\/span><\/span><\/span>fotograma anterior est\u00e1 desaparecendo <\/b><\/span><\/span><\/span>de nossa <\/b><\/span><\/span><\/span>mem\u00f3ria visual,<\/b><\/span><\/span><\/span> o que nos d\u00e1 a <\/b><\/span><\/span><\/span>sensa\u00e7\u00e3o de continuidade.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Filma-se <\/b><\/span><\/span><\/span>um <\/b><\/span><\/span><\/span>ventilador cujas p\u00e1s <\/b><\/span><\/span><\/span>est\u00e3o <\/b><\/span><\/span><\/span>girando no sentido hor\u00e1rio. <\/b><\/span><\/span><\/span>Este <\/b><\/span><\/span><\/span>ventilador possui quatro p\u00e1s simetricamente dispostas, uma das quais pintadas de cor diferente. <\/b><\/span><\/span><\/span><\/p>\n

Ao <\/b><\/span><\/span><\/span>projetarmos o filme, <\/b><\/span><\/span><\/span>os <\/b><\/span><\/span><\/span>fotogramas<\/b><\/span><\/span><\/span> aparecem na tela numa <\/b><\/span><\/span><\/span>sequ\u00eancia que nos d\u00e1 a sensa\u00e7\u00e3o de que as p\u00e1s est\u00e3o girando em sentido anti- hor\u00e1rio.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Desta forma, o <\/b><\/span><\/span><\/span>n\u00famero m\u00ednimo de rota\u00e7\u00f5es por segundo <\/b><\/span><\/span><\/span>que as p\u00e1s <\/b><\/span><\/span><\/span>devem estar efetuando<\/b><\/span><\/span><\/span>, para que <\/b><\/span><\/span><\/span>isto ocorra, <\/b><\/span><\/span><\/span>\u00e9 de:<\/b><\/span><\/span><\/span><\/p>\n

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

16-(FATEC-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Em um <\/b><\/span><\/span><\/span>est\u00e1dio esportivo, <\/b><\/span><\/span><\/span>uma <\/b><\/span><\/span><\/span>pista circular tem raio igual a 12,0 m. <\/b><\/span><\/span><\/span><\/p>\n

Dois atletas A e B <\/b><\/span><\/span><\/span>percorrem a pista no <\/b><\/span><\/span><\/span>mesmo sentido <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>velocidades constantes V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0= 8 m\/s e V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>\u00a0= 6m\/s. <\/b><\/span><\/span><\/span>Ambos passam por um <\/b><\/span><\/span><\/span>mesmo ponto na data zero.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

O <\/b><\/span><\/span><\/span>corredor mais veloz\u00a0<\/b><\/span><\/span><\/span>estar\u00e1 com <\/b><\/span><\/span><\/span>uma volta de vantagem <\/b><\/span><\/span><\/span>sobre o <\/b><\/span><\/span><\/span>outro na data: <\/b><\/span><\/span><\/span>(considere \u03c0 = 3)<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>35 s<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>15 s<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>20 s<\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>60 s<\/b><\/span><\/span><\/span><\/p>\n

e) <\/b><\/span><\/span><\/span>36 s<\/b><\/span><\/span><\/span><\/p>\n

17-(CEFET-CE)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Duas part\u00edculas <\/b><\/span><\/span><\/span>percorrem uma <\/b><\/span><\/span><\/span>mesma trajet\u00f3ria<\/b><\/span><\/span><\/span> em <\/b><\/span><\/span><\/span>movimentos circulares uniformes, uma<\/b><\/span><\/span><\/span> no <\/b><\/span><\/span><\/span>sentido hor\u00e1rio e a outra no sentido anti-hor\u00e1rio. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>primeira efetua 1\/3 rpm e a segunda 1\/4 rpm. <\/b><\/span><\/span><\/span>Sabendo que <\/b><\/span><\/span><\/span>partiram do mesmo ponto<\/b><\/span><\/span><\/span>, em <\/b><\/span><\/span><\/span>uma hora, quantas vezes se encontrar\u00e3o?<\/b><\/span><\/span><\/span><\/p>\n

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

18-(FGV-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma <\/b><\/span><\/span><\/span>grande manivela, quatro engrenagens pequenas de 10 dentes e outra de 24 dentes,<\/b><\/span><\/span><\/span> tudo associado a <\/b><\/span><\/span><\/span>tr\u00eas cilindros de 8 cm de di\u00e2metro, constituem este pequeno moedor manual de cana.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ao produzir <\/b><\/span><\/span><\/span>caldo de cana, <\/b><\/span><\/span><\/span>uma <\/b><\/span><\/span><\/span>pessoa gira a manivela <\/b><\/span><\/span><\/span>fazendo-a <\/b><\/span><\/span><\/span>completar uma volta a cada meio minuto.<\/b><\/span><\/span><\/span><\/p>\n

Supondo que a <\/b><\/span><\/span><\/span>vara de cana colocada entre os cilindros seja esmagada sem escorregamento, <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>velocidade escalar com que a m\u00e1quina puxa a cana para seu interior, em cm\/s<\/b><\/span><\/span><\/span>, \u00e9, aproximadamente,<\/b><\/span><\/span><\/span><\/p>\n

Dado: Se necess\u00e1rio <\/b><\/span><\/span><\/span>use \u03c0 = 3.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

19-(UEL-PR)<\/b><\/span><\/span><\/span> <\/b>O <\/b><\/span><\/span><\/span>cavalo<\/b><\/span><\/span><\/span> anda nas <\/b><\/span><\/span><\/span>pontas dos cascos.<\/b><\/span><\/span><\/span><\/p>\n

Nenhum <\/b><\/span><\/span><\/span>animal<\/b><\/span><\/span><\/span> se <\/b><\/span><\/span><\/span>parece tanto <\/b><\/span><\/span><\/span>com uma <\/b><\/span><\/span><\/span>estrela do corpo de bal\u00e9 <\/b><\/span><\/span><\/span>quanto um <\/b><\/span><\/span><\/span>puro sangue <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>perfeito equil\u00edbrio, <\/b><\/span><\/span><\/span>que a <\/b><\/span><\/span><\/span>m\u00e3o de quem o monta <\/b><\/span><\/span><\/span>parece <\/b><\/span><\/span><\/span>manter suspenso. <\/b><\/span><\/span><\/span><\/p>\n

Degas pintou-o <\/b><\/span><\/span><\/span>e procurou <\/b><\/span><\/span><\/span>concentrar todos os aspectos <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>fun\u00e7\u00f5es do cavalo de corrida: treinamento, velocidade, apostas e fraudes, beleza, eleg\u00e2ncia suprema.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ele foi um dos <\/b><\/span><\/span><\/span>primeiros a estudar as verdadeiras figuras do nobre animal em movimento, <\/b><\/span><\/span><\/span>por meio dos <\/b><\/span><\/span><\/span>instant\u00e2neos do grande Muybridge. <\/b><\/span><\/span><\/span>De resto, <\/b><\/span><\/span><\/span>amava e apreciava a fotografia, <\/b><\/span><\/span><\/span>em uma \u00e9poca em que os <\/b><\/span><\/span><\/span>artistas a desdenhavam ou n\u00e3o ousavam confessar que a utilizavam.<\/b><\/span><\/span><\/span><\/p>\n

Suponha que a <\/b><\/span><\/span><\/span>sequ\u00eancia de imagens apresentada na figura da esquerda foi obtida com o aux\u00edlio de c\u00e2meras fotogr\u00e1ficas dispostas a cada 1,5 m ao longo da trajet\u00f3ria do cavalo.<\/b><\/span><\/span><\/span><\/p>\n

Sabendo que a <\/b><\/span><\/span><\/span>frequ\u00eancia do movimento foi de 0,5 Hz, <\/b><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span>velocidade m\u00e9dia do cavalo <\/b><\/span><\/span><\/span>\u00e9:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

20-(UERJ-RJ)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>ciclista<\/b><\/span><\/span><\/span> <\/b>pedala uma bicicleta <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>trajet\u00f3ria circular <\/b><\/span><\/span><\/span>de modo que as <\/b><\/span><\/span><\/span>dire\u00e7\u00f5es dos deslocamentos das rodas mant\u00eam sempre um \u00e2ngulo de 60<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sup><\/span>. <\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>di\u00e2metro da roda traseira <\/b><\/span><\/span><\/span>dessa bicicleta <\/b><\/span><\/span><\/span>\u00e9 igual \u00e0 metade do di\u00e2metro de sua roda dianteira.<\/b><\/span><\/span><\/span>
\nO <\/b><\/span><\/span><\/span>esquema <\/b><\/span><\/span><\/span> <\/b>mostra<\/b><\/span><\/span><\/span> a bicicleta <\/b><\/span><\/span><\/span>vista de cima em um dado instante do percurso.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Admita<\/b><\/span><\/span><\/span> que, <\/b><\/span><\/span><\/span>para uma volta completa <\/b><\/span><\/span><\/span>da bicicleta<\/b><\/span><\/span><\/span>, N<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00e9 o n\u00famero de voltas dadas pela roda traseira <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>N<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0o n\u00famero de voltas dadas pela roda dianteira <\/b><\/span><\/span><\/span>em torno de seus <\/b><\/span><\/span><\/span>respectivos eixos de rota\u00e7\u00e3o.
\n<\/b><\/span><\/span><\/span>A <\/b><\/span><\/span><\/span>raz\u00e3o N<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\/N<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00e9 igual <\/b><\/span><\/span><\/span>a:<\/b><\/span><\/span><\/span><\/p>\n

(A) <\/b><\/span><\/span><\/span>1\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><\/p>\n

(B) <\/b><\/span><\/span><\/span>2\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><\/p>\n

(C) <\/b><\/span><\/span><\/span>3\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><\/p>\n

(D) <\/b><\/span><\/span><\/span>4\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><\/p>\n

(E) <\/b><\/span><\/span><\/span>5<\/b><\/span><\/span><\/span><\/p>\n

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

21-(PASUSP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma <\/b><\/span><\/span><\/span>bicicleta tem a roda dianteira com raio 27 cm e a roda traseira com raio 33 cm.<\/b><\/span><\/span><\/span><\/p>\n

Estando <\/b><\/span><\/span><\/span>a bicicleta parada, dois pontos A e B s\u00e3o marcados, <\/b><\/span><\/span><\/span>nas <\/b><\/span><\/span><\/span>rodas dianteira e traseira, <\/b><\/span><\/span><\/span>nos respectivos <\/b><\/span><\/span><\/span>pontos de contato com o solo, <\/b><\/span><\/span><\/span>conforme a figura.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Depois<\/b><\/span><\/span><\/span> de a bicicleta <\/b><\/span><\/span><\/span>percorrer uma dist\u00e2ncia d, os pontos A e B voltam a ficar, simultaneamente, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>contato com o solo.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Assumindo que <\/b><\/span><\/span><\/span>n\u00e3o h\u00e1 escorregamento das rodas da bicicleta, <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>menor valor de d, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>metros,<\/b><\/span><\/span><\/span> para o qual <\/b><\/span><\/span><\/span>essa situa\u00e7\u00e3o acontece, <\/b><\/span><\/span><\/span>\u00e9<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

22-(MACKENZIE-SP)<\/b><\/span><\/span><\/span><\/p>\n

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

Num <\/b><\/span><\/span><\/span>rel\u00f3gio convencional, \u00e0s 3h pontualmente, <\/b><\/span><\/span><\/span>vemos que o <\/b><\/span><\/span><\/span>\u00e2ngulo formado entre o ponteiro dos minutos e o das horas mede 90\u00b0. <\/b><\/span><\/span><\/span>\"\"<\/p>\n

A <\/b><\/span><\/span><\/span>partir desse instante, <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>menor intervalo de tempo<\/b><\/span><\/span><\/span>, necess\u00e1rio para que <\/b><\/span><\/span><\/span>esses ponteiros fiquem exatamente um sobre o outro, \u00e9<\/b><\/span><\/span><\/span><\/p>\n

(A) <\/b><\/span><\/span><\/span>15 minutos. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

(B) <\/b><\/span><\/span><\/span>16 minutos\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

(C) <\/b><\/span><\/span><\/span>180\/11 minutos. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

(D) <\/b><\/span><\/span><\/span>360\/21 minutos. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

(E) <\/b><\/span><\/span><\/span>17,5 minutos.<\/b><\/span><\/span><\/span><\/p>\n

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

23-(ITA-SP)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Entre <\/b><\/span><\/span><\/span>duas superposi\u00e7\u00f5es consecutivas <\/b><\/span><\/span><\/span>dos <\/b><\/span><\/span><\/span>ponteiros das horas e dos minutos de um rel\u00f3gio, <\/b><\/span><\/span><\/span>o <\/b><\/span><\/span><\/span>ponteiro dos minutos varre um \u00e2ngulo cuja medida, em radianos<\/b><\/span><\/span><\/span>, \u00e9 <\/b><\/span><\/span><\/span>igual<\/b><\/span><\/span><\/span> a<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

24- (UFJF-MG)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Na <\/b><\/span><\/span><\/span>figura abaixo, <\/b><\/span><\/span><\/span>quando o <\/b><\/span><\/span><\/span>ponteiro dos segundos do rel\u00f3gio est\u00e1 apontando para B, <\/b><\/span><\/span><\/span>uma <\/b><\/span><\/span><\/span>formiga<\/b><\/span><\/span><\/span> <\/b>parte do ponto A <\/b><\/span><\/span><\/span>e se desloca com <\/b><\/span><\/span><\/span>velocidade angular constante W = 2\u03c0 rad\/min, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>sentido anti-hor\u00e1rio.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Ao <\/b><\/span><\/span><\/span>completar uma volta<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>quantas vezes a formiga ter\u00e1 cruzado com o ponteiro dos segundos?<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>zero\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>uma\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><\/p>\n

c) <\/b><\/span><\/span><\/span>duas\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><\/p>\n

d) <\/b><\/span><\/span><\/span>tr\u00eas\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><\/p>\n

e) <\/b><\/span><\/span><\/span>\u03c0<\/b><\/span><\/span><\/span><\/p>\n

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

25-(FUVEST-SP)\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Dois carros <\/b><\/span><\/span><\/span>percorrem <\/b><\/span><\/span><\/span>uma pista circular, de raio R, <\/b><\/span><\/span><\/span>no <\/b><\/span><\/span><\/span>mesmo sentido, <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>velocidades de m\u00f3dulos constantes<\/b><\/span><\/span><\/span> e <\/b><\/span><\/span><\/span>iguais a v e 3v. <\/b><\/span><\/span><\/span>O <\/b><\/span><\/span><\/span>tempo decorrido <\/b><\/span><\/span><\/span>entre <\/b><\/span><\/span><\/span>dois encontros sucessivos <\/b><\/span><\/span><\/span>vale:<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>\u03c0 R\/3v.\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><\/p>\n

b) <\/b><\/span><\/span><\/span>2\u03c0 R\/3v.\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><\/p>\n

c) <\/b><\/span><\/span><\/span>\u03c0 R\/v.\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><\/p>\n

d) <\/b><\/span><\/span><\/span>2\u03c0 R\/v.\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><\/p>\n

e) <\/b><\/span><\/span><\/span>3\u03c0 R\/v.<\/b><\/span><\/span><\/span><\/p>\n

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

26-(OBF)<\/b><\/span><\/span><\/span><\/p>\n

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

\"\"<\/p>\n

Beto e Pedro <\/b><\/span><\/span><\/span>s\u00e3o <\/b><\/span><\/span><\/span>dois malabaristas em monociclos onde os pedais acionam diretamente os eixos das rodas.<\/b><\/span><\/span><\/span><\/p>\n

Para que se <\/b><\/span><\/span><\/span>mantenham lado a lado, <\/b><\/span><\/span><\/span>em <\/b><\/span><\/span><\/span>movimento uniforme, Beto d\u00e1 3 pedaladas completas por segundo enquanto Pedro d\u00e1 apenas 2. <\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>monociclo de Beto tem raio de 30 cm.<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>qual o <\/b><\/span><\/span><\/span>raio do monociclo de Pedro?<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>num <\/b><\/span><\/span><\/span>determinado instante, <\/b><\/span><\/span><\/span>qual a <\/b><\/span><\/span><\/span>velocidade do ponto de contato da roda com a pista, <\/b><\/span><\/span><\/span>admitindo que n\u00e3o ocorra deslizamento? E <\/b><\/span><\/span><\/span>de um ponto diametralmente oposto ao ponto de contato?<\/b><\/span><\/span><\/span><\/p>\n

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

27-(UFC-CE)\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um <\/b><\/span><\/span><\/span>autom\u00f3vel se desloca em uma estrada horizontal <\/b><\/span><\/span><\/span>com <\/b><\/span><\/span><\/span>velocidade constante <\/b><\/span><\/span><\/span>de modo tal que <\/b><\/span><\/span><\/span>os <\/b><\/span><\/span><\/span>\"\"<\/p>\n

seus pneus rolam sem qualquer deslizamento na pista. <\/b><\/span><\/span><\/span><\/p>\n

Cada pneu tem di\u00e2metro D = 0,50 m <\/b><\/span><\/span><\/span>e um <\/b><\/span><\/span><\/span>medidor colocado em um deles registra uma freq\u00fc\u00eancia<\/b><\/span><\/span><\/span> de <\/b><\/span><\/span><\/span>840 rpm. <\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>velocidade do autom\u00f3vel <\/b><\/span><\/span><\/span>\u00e9, <\/b><\/span><\/span><\/span>aproximadamente,<\/b><\/span><\/span><\/span> de: (considere \u03c0 = 3).<\/b><\/span><\/span><\/span><\/p>\n

a) <\/b><\/span><\/span><\/span>32,4km\/h\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) <\/b><\/span><\/span><\/span>43,2km\/h\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

c) <\/b><\/span><\/span><\/span>54,0km\/h\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

d) <\/b><\/span><\/span><\/span>64,8km\/h\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><\/p>\n

e) <\/b><\/span><\/span><\/span>75,6km\/h<\/b><\/span><\/span><\/span><\/p>\n

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

28-(UEM-PR)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um\u00a0<\/b><\/span><\/span><\/span>modelo padr\u00e3o\u00a0<\/b><\/span><\/span><\/span>para dar <\/b><\/span><\/span><\/span>movimento a uma bicicleta <\/b><\/span><\/span><\/span>consiste em\u00a0<\/b><\/span><\/span><\/span>duas polias conectadas <\/b><\/span><\/span><\/span>por uma<\/b><\/span><\/span><\/span>\"\"<\/p>\n

corrente.<\/b><\/span><\/span><\/span><\/p>\n

Uma das polias, <\/b><\/span><\/span><\/span>chamada de\u00a0<\/b><\/span><\/span><\/span>coroa,<\/b><\/span><\/span><\/span> fica\u00a0<\/b><\/span><\/span><\/span>conectada aos pedais, <\/b><\/span><\/span><\/span>enquanto a <\/b><\/span><\/span><\/span>outra polia,<\/b><\/span><\/span><\/span> chamada de\u00a0<\/b><\/span><\/span><\/span>catraca,<\/b><\/span><\/span><\/span> fica <\/b><\/span><\/span><\/span>acoplada \u00e0 roda\u00a0traseira da bicicleta.\u00a0<\/b><\/span><\/span><\/span><\/p>\n

Cada pedalada, <\/b><\/span><\/span><\/span>isto \u00e9, <\/b><\/span><\/span><\/span>cada giro completo dos\u00a0pedais, <\/b><\/span><\/span><\/span>corresponde a <\/b><\/span><\/span><\/span>um\u00a0giro completo da coroa, <\/b><\/span><\/span><\/span>enquanto <\/b><\/span><\/span><\/span>cada volta completa da catraca corresponde a uma volta completa da roda \u00e0 qual est\u00e1 acoplada.\u00a0<\/b><\/span><\/span><\/span><\/p>\n

Sabe-se, <\/b><\/span><\/span><\/span>ainda, que o\u00a0<\/b><\/span><\/span><\/span>n\u00famero de\u00a0voltas da catraca \u00e9 proporcional ao n\u00famero de voltas da coroa, <\/b><\/span><\/span><\/span>com\u00a0<\/b><\/span><\/span><\/span>raz\u00e3o de propor\u00e7\u00e3o igual \u00e0 raz\u00e3o entre os raios da coroa (<\/b><\/span><\/span><\/span>R<\/b><\/i><\/span><\/span><\/span>) e da catraca (<\/b><\/span><\/span><\/span>r<\/b><\/i><\/span><\/span><\/span>).\u00a0<\/b><\/span><\/span><\/span><\/p>\n

Considerando que a <\/b><\/span><\/span><\/span>bicicleta, a partir do modelo\u00a0apresentado,\u00a0<\/b><\/span><\/span><\/span>desloca-se <\/b><\/span><\/span><\/span>em linha reta em uma superf\u00edcie plana\u00a0e que n\u00e3o haja deslizamento entre as rodas da bicicleta e a superf\u00edcie,\u00a0assinale<\/b><\/span><\/span><\/span> o que <\/b><\/span><\/span><\/span>for\u00a0correto.<\/b><\/span><\/span><\/span><\/p>\n

01) <\/b><\/span><\/span><\/span>Se <\/b><\/span><\/span><\/span>os raios da coroa e da catraca <\/b><\/span><\/span><\/span>s\u00e3o, respectivamente,\u00a0<\/b><\/span><\/span><\/span>R\u00a0<\/b><\/i><\/span><\/span><\/span>e\u00a0<\/b><\/span><\/span><\/span>r<\/b><\/i><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>ent\u00e3o <\/b><\/span><\/span><\/span>cada volta completa da<\/b><\/span><\/span><\/span><\/p>\n

coroa corresponde a\u00a0<\/b><\/span><\/span><\/span>R\/r\u00a0<\/b><\/i><\/span><\/span><\/span>voltas da catraca.<\/b><\/span><\/span><\/span><\/p>\n

02) <\/b><\/span><\/span><\/span>Para um <\/b><\/span><\/span><\/span>dado\u00a0<\/b><\/span><\/span><\/span>R\u00a0<\/b><\/i><\/span><\/span><\/span>fixo, <\/b><\/span><\/span><\/span>quanto <\/b><\/span><\/span><\/span>menor for o raio da catraca,<\/b><\/span><\/span><\/span> <\/b>maior<\/b><\/span><\/span><\/span> ser\u00e1 o <\/b><\/span><\/span><\/span>deslocamento da bicicleta por pedalada realizada.<\/b><\/span><\/span><\/span><\/p>\n

04) <\/b><\/span><\/span><\/span>As <\/b><\/span><\/span><\/span>velocidades angulares da coroa e da catraca s\u00e3o sempre iguais, <\/b><\/span><\/span><\/span>independentemente do valor <\/b><\/span><\/span><\/span>de seus raios.<\/b><\/span><\/span><\/span><\/p>\n

08) <\/b><\/span><\/span><\/span>Se a <\/b><\/span><\/span><\/span>coroa de uma bicicleta tem raio igual a 15 cm, <\/b><\/span><\/span><\/span>e a <\/b><\/span><\/span><\/span>catraca tem raio igual a 1\/5 do raio da roda <\/b><\/span><\/span><\/span>e <\/b><\/span><\/span><\/span>1\/4 do raio da coroa, <\/b><\/span><\/span><\/span>ent\u00e3o <\/b><\/span><\/span><\/span>cada pedalada corresponde a um deslocamento de 1,5 m.<\/b><\/span><\/span><\/span><\/p>\n

16) <\/b><\/span><\/span><\/span>Se as <\/b><\/span><\/span><\/span>rodas de uma bicicleta t\u00eam raio igual a 50 cm <\/b><\/span><\/span><\/span>e se o <\/b><\/span><\/span><\/span>raio da coroa \u00e9 o dobro do raio da catraca,<\/b><\/span><\/span><\/span> ent\u00e3o um <\/b><\/span><\/span><\/span>ciclista que realiza duas pedaladas por segundo nessa bicicleta movimenta-se a 4\u03c0<\/b><\/span><\/span><\/span>\uf020<\/b><\/span><\/span><\/span>m\/s.<\/b><\/span><\/span><\/span><\/p>\n

29-(UERJ-RJ)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma <\/b><\/span><\/span><\/span>m\u00e1quina possui duas engrenagens circulares, <\/b><\/span><\/span><\/span>sendo a <\/b><\/span><\/span><\/span>dist\u00e2ncia entre seus centros A e B igual<\/b><\/span><\/span><\/span><\/p>\n

a 11 cm, como mostra o esquema:<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Sabe-se que a <\/b><\/span><\/span><\/span>engrenagem menor d\u00e1 1000 voltas no mesmo tempo em que a maior d\u00e1 375 voltas, <\/b><\/span><\/span><\/span>e que os <\/b><\/span><\/span><\/span>comprimentos dos dentes de ambas t\u00eam valores desprez\u00edveis.<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span>medida,<\/b><\/span><\/span><\/span> em <\/b><\/span><\/span><\/span>cent\u00edmetros, do raio da engrenagem menor <\/b><\/span><\/span><\/span>equivale a:<\/b><\/span><\/span><\/span><\/p>\n

(A) <\/b><\/span><\/span><\/span>2,5 <\/b><\/span><\/span><\/span><\/p>\n

(B) <\/b><\/span><\/span><\/span>3,0 <\/b><\/span><\/span><\/span><\/p>\n

(C) <\/b><\/span><\/span><\/span>3,5 <\/b><\/span><\/span><\/span><\/p>\n

(D) <\/b><\/span><\/span><\/span>4,0<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

Confira a resolu\u00e7\u00e3o comentada dos exerc\u00edcios<\/a><\/span><\/h3>\n","protected":false},"excerpt":{"rendered":"

MOVIMENTO CIRCULAR UNIFORME (MCU) FORMUL\u00c1RIO Per\u00edodo e frequ\u00eancia Velocidade escalar (linear) V de um MCU Velocidade angular (W) de um MCU Rela\u00e7\u00e3o entre velocidade escalar (V) e velocidade angular (W) Acoplamento de polias e engrenagens Exerc\u00edcios de vestibulares com resolu\u00e7\u00f5es comentadas sobre Movimento Circular Uniforme \u00a0 01-(UNESP-SP) Quem est\u00e1 na Terra v\u00ea sempre a mesma face da lua. Isto ocorre<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2508,"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-2535","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2535","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=2535"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2535\/revisions"}],"predecessor-version":[{"id":2540,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2535\/revisions\/2540"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2508"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=2535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}