When a ball is incident obliquely on a flat surface, the rebound spin, speed, and angle generally
differ from the corresponding incident values. Measurements of all three quantities were made using
a digital video camera to film the bounce of a tennis ball incident with zero spin at various angles
on several different surfaces. The maximum spin rate of a spherical ball is determined by the
condition that the ball commences to roll at the end of the impact. Under some conditions, the ball
was found to spin faster than this limit. This result can be explained if the ball or the surface stores
energy elastically due to deformation in a direction parallel to the surface. The latter effect was
investigated by comparing the bounce of a tennis ball with that of a superball. Ideally, the coefficient
of restitution ~COR! of a superball is 1.0 in both the vertical and horizontal directions. The COR for
the superball studied was found to be 0.76 in the horizontal direction, and the corresponding COR
for a tennis ball was found to vary from 20.51 to 10.24 depending on the incident angle and the
coefficient of sliding friction