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 increases.
B)the moment of inertia of the system decreases and the angular speed decreases.
C)the moment of inertia of the system decreases and the angular speed remains the same.
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, his distance from the axis of rotation decreases, which reduces the moment of inertia of the system. According to the law of conservation of angular momentum, the product of moment of inertia and angular velocity must remain constant. Therefore, if the moment of inertia decreases, the angular velocity must increase to keep their product constant. Hence, the correct choice is A.

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