(solution) A plank of length L : 1.5 m rests on two identical rotating

(solution) A plank of length L : 1.5 m rests on two identical rotating

A plank of length L : 1.5 m rests on two identical rotating wheels. The distance between the wheels is D : 1 m and the coefficient of friction between the plank and the surface of the wheels is ? : 0.1. The rotational speed of the wheels is ?, and the directions of the rotations are opposite to each other. Show that for small displacements the plank oscillates and calculate the period of the oscillation