Halliday, Resnick & Walker — Rolling, Torque, and Angular Momentum: Problem 39_E

The angular momentum of a flywheel having a rotational inertia of \(0.140 \text{ kg} \cdot \text{m}^2\) about its central axis decreases from \(3.00\) to \(0.800 \text{ kg} \cdot \text{m}^2/\text{s}\) in \(1.50 \text{ s}\). (a) What is the magnitude of the average torque acting on the flywheel about its central axis during this period? (b) Assuming a constant angular acceleration, through what angle does the flywheel turn? (c) How much work is done on the wheel? (d) What is the average power of the flywheel?