Multicomponent models of friction

The problem of motion of a homogeneous ball on a horizontal plane is considered. It is assumed that the contact patch is of spherical shape, whereas the pressure center does not coincide with the center of the contact patch and is displaced in the sliding direction of the ball. The friction force has two components that are parallel and perpendicular to the sliding velocity; the friction force moment has a vertical component and two horizontal components being parallel and perpendicular to the sliding velocity.