A turntable (a flat disk) of mass 5.0-kg is rotating at a constant speed when your finger makes contact with the outer edge, as shown in the animation (position of a point on the outer edge of the turntable is shown in meters and time is shown in seconds). Friction between your finger and the turntable causes the turntable to stop.
What is the average torque on the turntable caused by the frictional force? Start