Question

An ice skater or a ballet dancer can decrease her angular velocity by folding her arms and bringing the stretched leg close to the other leg.

(a) True

(b) False

I had been asked this question in examination.

My enquiry is from Significance of Rotational Motion topic in portion System of Particles and Rotational Motion of Engineering Physics I

Answer 1

The correct choice is (b) False

Explanation: An ice skater can increase her angular velocity by folding her arm and bringing the leg closer to the other. When she stretches her hand outward, her moment of inertia increases and hence angular speed decreases to conserve angular momentum. When she folded her hands and brings the stretched legs close to the other leg, her moment of inertia decreases and hence her angular speed increases.