An ice skater spins with her arms outstretched at 1 revolution per second. She pulls her arms in toward her body. Does her angular momentum change? Ignore friction with the ice.

Her angular momentum does not change.

Explanation:

Conservation of angular momentum: It states that there is no change in the angular momentum when no torque outside the system is applied to the body.

In the given problem, an ice skater spins her arm outstretched. She pulls her arms in towards her body.

The angular momentum of an ice skaters remains same as the there is no external torque applied on an ice skater. The initial angular momentum  and the final angular momentum of the given system are same. Therefore, the angular momentum is conserved.

Therefore, her angular momentum does not change.