A figure skater with arms initially extended starts spinning on the ice at 3 rad/s.She then pulls her arms in close to her body.Which of the following results?
A)a smaller rotational rate
B)a greater rotational rate
C)a greater angular momentum
D)a smaller angular momentum

Question

Quizplus · Accepted Answer

When the figure skater pulls her arms in close to her body, her moment of inertia decreases because she is reducing the distance of the mass from the axis of rotation. As a result, her angular velocity (rotational rate) must increase in order to conserve angular momentum. This is described by the equation L=Iω, where L is angular momentum, I is moment of inertia, and ω is angular velocity. Therefore, a greater rotational rate is the correct answer.

A Figure Skater with Arms Initially Extended Starts Spinning on the Ice