A small ball with mass 1.30 kg is mounted on one end of a rod 0.780 m long and of negligible mass. The system rotates in a horizontal circle about the other end of the rod at 5010 rev/min.

(a) Calculate the rotational inertia of the system about the axis of rotation.

(b) There is an air drag of 2.30 x 10-2 N on the ball, directed opposite its motion. What torque must be applied to the system to keep it rotating at constant speed?