A 6-kg bowling ball with a radius of 14 cm is spinning about a vertical axis (with its center of mass motionless) at an initial rate of 3 turns per second. Friction with the floor, however, causes the bowling ball to rotate more and more slowly until it stops after about 22s. What was the average torque that the friction interaction applied to the bowling ball?

Question

A 6-kg bowling ball with a radius of 14 cm is spinning about a vertical axis (with its center of mass motionless) at an initial rate of 3 turns per second.  Friction with the floor, however, causes the bowling ball to rotate more and more slowly until it stops after about 22s.  What was the average torque that the friction interaction applied to the bowling ball?