Two heavy masses are placed at opposite ends of a platform that rotates around its center. A torque is applied to the platform's axle.

The system is released from rest, and the platform begins to rotate with a particular angular acceleration.

If the experiment is performed again with the masses closer to the center of the platform, what will happen?

1. The angular acceleration will be smaller.
2. The angular acceleration will stay the same.
3. The angular acceleration will be larger.

According to Newton's Second Law, Στ = I α. The torque is the same in the two cases. Moving the masses closer to the center reduces the moment of inertia and increases the angular acceleration.