A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, it is true to say that
A) the moment of inertia of the system decreases and the angular speed decreases.
B) the moment of inertia of the system decreases and the angular speed remains the same.
C) the moment of inertia of the system decreases and the angular speed increases.
D) the moment of inertia of the system increases and the angular speed increases.
E) the moment of inertia of the system increases and the angular speed decreases.

Question

Quizplus · Accepted Answer

When Diego moves towards the center of the merry-go-round, the moment of inertia of the system decreases because the distribution of mass is closer to the axis of rotation. According to the conservation of angular momentum, if the moment of inertia decreases, the angular speed must increase to keep the angular momentum constant.

A Merry-Go-Round Spins Freely When Diego Moves Quickly to the Center