(a) A student rotates on a frictionless piano stool with his arms outstretched, a heavy weight in each hand. Suddenly he lets go of the weights, and they fall to the floor. As a result, does the student's angular speed increase, decrease, or stay the same?

(b) Choose the best explanation from among the following:

I. The loss of angular momentum when the weights are dropped causes the student to rotate more slowly.

II. The student's moment of inertia is decreased by dropping the weights.

III. Dropping the weights exerts no torque on the student, but the floor exerts a torque on the weights when they land.