When a man on a frictionless rotating stool extends his arms horizontally, his rotational kinetic energy:
A)must increase
B)must decrease
C)must remain the same
D)may increase or decrease depending on his initial angular velocity
E)may increase or decrease depending on his angular acceleration

Question

Quizplus · Accepted Answer

When the man extends his arms horizontally, he increases his moment of inertia. Therefore, in order to conserve angular momentum, his angular velocity must decrease, resulting in a decrease in his rotational kinetic energy.

When a Man on a Frictionless Rotating Stool Extends His