A disk with a mass of 18.5 kg, a diameter of 36.5 cm, and a thickness of 6.09 cm is mounted on a rough horizontal axle as shown on the left in the figure. (There is a friction force between the axle and the disk). The disk is initially at rest. A constant force, F = 60.7 N, is applied to the edge of the disk at an angle of 37.0°, as shown on the right in the figure. After 2.00 s, the force is reduced to F = 21.7 N, and the disk spins with a constant angular velocity.

Question

anonymous · Answer

a) What is the magnitude of the torque due to friction between the disk and the axle? 
b) What is the angular velocity of the disk after 2.00 s? 
c) What is the kinetic energy of the disk after 2.00 s?