CONDITIONS FOR THE ONSET OF SLIDING IN A PLANE SYSTEM WITH FRICTION

The problem of the plane motion of a rigid body along a fixed surface in the presence of dry (Coulomb) friction is considered. The constrain t is assumed to be non-restraining. It is shown that the validity of a certain system of two inequalities of the same type guarantees that t he surfaces maintain contact and that the body will continue to roll w ithout sliding. These conditions are analysed in a few specific cases of mechanical systems.