Adjustable Moment of Inertia

Two heavy cylindrical masses are placed at opposite ends of a platform that rotates around its center. A torque is applied to the platform's axle by means of a string. The string passes over a pulley and a mass hangs from the other end of the string.

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

If the experiment is performed a second time with the masses moved closer to the center of the platform, what will happen?

  1. The angular acceleration will decrease.
  2. The angular acceleration will stay the same.
  3. The angular acceleration will increase.