Question

Assertion: A centripetal force can't do any work on a body undergoing uniform circular motion.

Reason: During the uniform circular motion, the force and displacement are always perpendicular to each other.

Options

• If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

• If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.

• If Assertion is true, but the Reason is false.

• If Assertion is false, but the Reason is true.

Answer 1

If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

Explanation:

A centripetal force does no work on a body undergoing uniform circular motion because it does not cause displacement in the direction of the force. Therefore, the Assertion (A) is true.

In uniform circular motion, the centripetal force acts towards the centre of the circle, while the instantaneous displacement is along the tangent. Hence, the force and displacement are perpendicular to each other. Therefore, the Reason (R) is true and correctly explains the Assertion.

Hence, both A and R are true and R is the correct explanation of A.