A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 1.00 m and a mass of 475 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 5,500 rev/min.
(a) Find the kinetic energy stored in the flywheel.
___________J
(b) If the flywheel is to supply energy to the car as a 20.0-hp motor would, find the length of time the car could run before the flywheel would have to be brought back up to speed.
____________ h