An Ice Skater Performs a Pirouette (A Fast Spin) by Pulling

Multiple Choice

An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his moment of inertia about the axis of rotation?

A) It changes, but it is impossible to tell which way.
B) It does not change.
C) It decreases.
D) It increases.