Problem 18CQ

Describe how work is done by a skater pulling in her arms during a spin. In particular, identify the force she exerts on each arm to pull it in and the distance each moves, noting that a component of the force is in the direction moved. Why is angular momentum not increased by this action?

Solution to 18CQ

Step 1 of 4

We need to describe how the work is done when a skater is pulling her arms when she spins. We need to identify the forces she exerts on each arm to pull the arms. And, we need to explain why the angular momentum does not increase.