What happens to a spinning ice skater's angular velocity when she brings her arms closer to her body?

When a spinning ice skater brings her arms closer to her body, her mass moment of inertia decreases. The mass moment of inertia is a measure of how mass is distributed with respect to the axis of rotation. When the arms are extended, the skater has a larger radius of gyration, resulting in a greater moment of inertia. As she draws her arms in, she is effectively reducing this distance, leading to a decrease in her moment of inertia.

According to the principle of conservation of angular momentum, the total angular momentum of the skater must remain constant if there are no external torques acting on her. The equation for angular momentum (L) can be expressed as:

L = Iω

where I is the moment of inertia and ω is the angular velocity. When the skater decreases her moment of inertia (I) by pulling her arms inward, her angular velocity (ω) must increase to keep the angular momentum (L) constant. Therefore, the correct statement is that her mass moment of inertia decreases while maintaining constant angular momentum. This relationship allows the skater to spin faster as she adjusts her body position.

In this scenario, the option highlighting the decrease in mass moment of inertia aligns with the physics of rotational motion and the