A classical experiment revisited:: The bounce of balls and superballs in three dimensions

A description of the inelastic collision of a ball when it bounces on a rigid horizontal surface with arbitrary initial spin conditions is presented. I consider cases where rebound occurs with and without sliding, and when the ball grips the surface. Two rebound models are discussed in which friction is described in terms of the static and dynamic coefficients of friction and the friction is expressed in terms of horizontal coefficients of restitution. The azimuthal and vertical deviation angles of the ball after impact are predicted as a function of the incident angle. We present data from an experiment in which a ball is launched horizontally from the edge of the laboratory bench and then rebounds on a horizontal surface. Ordinary balls exhibit two rebound regimes, with and without sliding, and can be satisfactorily described by the first model. Superballs exhibit a grip behavior whose description requires the use of the second model. (C) 2005 American Association of Physics Teachers.