What is torque 'τ' in a circular motion?
Correct answer: B. τ = mr2α
- A. τ = mr2π
- B. τ = mr2α
- C. τ = mrα
- D. τ = mr2 /α
Explanation
Explanation:Torque in circular motion is the rotational equivalent of force in linear motion. It is a measure of the rotational force that causes an object to rotate about an axis. The torque is given by the product of the moment of inertia (mr²) and the angular acceleration (α) of the rotating object. Torque = Iα = mr²α (I = mr²)This option is not correct because π is not related to the torque.This option is also incorrect because it does not include the distance from the axis of rotation (r). This option is also incorrect because it is the reciprocal of the correct formula of torque.
This question appeared on the UHS MDCAT 2009 paper, which you can sit online with every answer explained.
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Rotational motion relates angular displacement, angular velocity and angular acceleration to linear displacement, tangential velocity and tangential acceleration through the radius. Questions use radians, v equals r omega and tangential acceleration, while distinguishing tangential velocity from centripetal acceleration and angular quantities from their linear counterparts.
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