Question

A piece of putty is initially located at point A on the rim of a grinding wheel rotating about a horizontal axis. The putty is dislodged from point A when the diameter through A is horizontal. The putty then rises vertically and returns to A the instant the wheel completes one revolution

Find the speed of a point on the rim of the wheel in terms of the acceleration due to gravity and the radius R of the wheel. (Use m, and g as necessary.) If the mass of the putty is m, what is the magnitude of the force that held it to the wheel? (Use m, and g as necessary.)