Presents the theoretical explanation of the observation that when a pen that is stuck in a hard rubber ball and dropped, the pen may bounce to several times the dropped height. Includes the procedure and models created to explain the observations. (DS)

Discusses an experiment on the conservation of momentum and Q-values for elastic and inelastic collisions with frictional energy dissipation taken into account. Indicates that the apparatus is readily fabricated from easily available materials. (CC)