Question

If a person standing on a rotating disc stretches out his hands, the angular speed will ___________

(a) Increase

(b) Decrease

(c) Remains same

(d) Increases and then decreases

I got this question by my college professor while I was bunking the class.

My question is taken from Moment of Inertia and its Significance topic in portion System of Particles and Rotational Motion of Engineering Physics I

Answer 1

The correct choice is (b) Decrease

To explain I would say: As the person stretches out his hands, his moment of inertia increases. To conserve angular momentum, his angular speed increases.