A man, with his arms at his sides, is spinning on a light frictionless turntable.When he extends his arms:
A)his angular velocity increases
B)his angular velocity remains the same
C)his rotational inertia decreases
D)his rotational kinetic energy increases
E)his angular momentum remains the same

Question

Quizplus · Accepted Answer

When the man extends his arms, his rotational inertia increases, which causes his angular velocity to decrease in order to conserve angular momentum. Angular momentum is conserved because there are no external torques acting on the system.

A Man, with His Arms at His Sides, Is Spinning