Name: bicycle torque and moment about an axis
Uploaded: 2023-09-22T11:49:21.000Z
Duration: 1 min 28 s
Channel: JoVE

Considere um ciclista andando de bicicleta e aplicando força no pedal para girar a roda. Quando uma força é exercida no pedal, a corrente anexada exerce uma força nas engrenagens da roda. A roda gira em torno de seu eixo, de modo que o eixo de rotação passa por ela.
O momento de uma força ao longo do eixo mede o quanto a força faz com que um objeto gire em torno de um ponto ou eixo específico.
Nesse caso, a roda gira em torno do eixo y no plano x-z. Aqui, o braço de momento ou a distância perpendicular entre o eixo de rotação e a linha de ação da força é o raio das engrenagens.
Portanto, o momento de uma força em torno do eixo y é igual a Frsinθ.
Como a força é tangencial, o ângulo entre o vetor de força e o raio é de 90 graus.
Em uma bicicleta, o momento de força pode ser multiplicado pela velocidade angular do eixo para obter a potência gerada pela rotação da roda.

<ol>
	<li>Hibbeler, R.C. (2016). Engenharia Mecânica \u2012 Estática e Dinâmica. Hoboken, Nova Jersey: Pearson Prentice Hall. pág. 145.</li>
</ol>

momento de uma força em relação a um eixo: escalar

Moment of a Force About an Axis: Scalar

O momento de uma força em relação a um eixo é um conceito crucial na mecânica que ajuda a determinar o movimento de rotação de um objeto's em torno de um ponto ou eixo específico. O momento de uma força pode ser calculado usando análise escalar, que envolve considerar a distância perpendicular entre o eixo de rotação e a linha de ação da força, ou simplesmente o braço de momento.

Para entender melhor o conceito de momento de uma força, considere o exemplo de um ciclista pedalando uma bicicleta. Quando o ciclista aplica força no pedal, a corrente acoplada exerce uma força no eixo da roda, fazendo-a girar. Aqui, o eixo de rotação passa pelo eixo da roda e o braço de momento é o raio do eixo. Nesse caso, o momento da força em relação ao eixo de rotação é dado por:



<img alt="Equation 1" src="/files/ftp_upload/14258/14258_Equation_1v2.svg" style="text-align: center; height: 13px;" />



onde, F é a força aplicada, r é o raio do eixo e θ é o ângulo entre o vetor de força e o raio. Como a força é tangencial, o ângulo entre o vetor de força e o raio é de 90 graus.

Em uma bicicleta, o momento de uma força pode ser multiplicado pela velocidade angular do eixo para obter a potência gerada pela rotação da roda. O momento de uma força é essencial no projeto de várias estruturas e máquinas, incluindo bicicletas, automóveis e aeronaves, para garantir sua estabilidade e segurança.

Momento de uma Força em relação a um Eixo: Escalar

O momento de uma força em torno de um eixo é um conceito crucial na mecânica que ajuda a determinar o movimento rotacional de um objeto em torno de um ponto específico ou ...

Education

JoVE Core

Mechanical Engineering

Engenharia Mecânica

Unit 1

Unidade 1

Force System Resultants

Resultantes de Sistemas de Forças

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

bicycle torque and moment about an axis

The moment of a force about an axis describes how a force can make an object turn around a fixed line. In scalar analysis, the moment is found from the perpendicular distance between the axis of rotation and the line of action of the force. That distance is called the moment arm.

A bicycle gives a clear example of this idea. When the cyclist pushes on the pedal, the chain applies a force to the wheel’s axle and makes it rotate. The axis of rotation passes through the axle, and the moment arm is the axle radius.

For this case, the moment of force about the axis depends on the force, the radius, and the angle between the force vector and the radius. Because the force is tangential, that angle is 90 degrees. The moment of force can also be multiplied by the angular velocity of the axle to find the power produced by the wheel rotation.

This concept is important in the design of bicycles, automobiles, and aircraft. Engineers use it to help maintain stability and safety in these machines and structures.

Bicycle Torque and Moment About an Axis

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key terms and concepts

Learn how the moment of a force about an axis is found with scalar analysis, using a bicycle axle example and its link to rotational power.

Bicycle Torque and Moment About an Axis | JoVE K12

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mechanical engineering

Bicycle Torque and Moment About an Axis

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