The fly-wheel of an old steam engine is a solid homogeneous metal disk of mass M = 117 kg and radius R = 80 cm. The engine rotates the wheel at 540 rpm. In the emergency, to bring the engine to stop, the fly-wheel is disengaged from the engine and a brake pad is applied at the edge to give a radially inward force F = 130 N. When the coefficient of kinetic friction among the pad and the fly-wheel is µk = 0.2, then how many revolutions does the fly-wheel make before coming to rest?
Determine how long does it take for the fly-wheel to come to rest?
Compute the work done by the torque throughout this time.