Question
Physics Question on System of Particles & Rotational Motion
A person is standing on a rotating table with metal spheres in his hands. If he withdraws his hands to his chest, then the effect on his angular velocity will be
A
increase
B
decrease
C
remain same
D
can t say
Answer
increase
Explanation
Solution
When the person withdraws his hands to his chest, his moment of inertia decreases. No external torque is acting on the system. So to conserve angular momentum, the angular velocity increases.