A grinding wheel of mass 5 kg rotates at constant speed when an object makes contact with the outer edge as shown in the animation (position of a point on the outer edge of the wheel is shown in meters and time is shown in seconds). Friction causes the wheel to stop. What is the average torque on the wheel by the frictional force? Start
The net torque on the wheel is proportional to the wheel's angular acceleration and its moment of inertia. See Giancoli 8-6.