Movement of spheres on rotating discs - A new method to measure coefficients of rolling friction by the central drift (Q1080668)

A sphere freely rolling without slipping on a rotating platform moves on stable circular orbits with regard to the laboratory system. The center of the sphere may even rest at a given place while the sphere spins around. If a force parallel to the plane of the rotating disc acts on the sphere a drift movement results perpendicular to the force. In the case of rolling resistance a drift of the sphere to the center of rotation can be observed. This effect is used to measure coefficients of rolling friction. Furthermore with rotating cones and funnels there exist stable modes of movement on orbits around the cone or funnel.