Normal impact of a ball rotating around its linear velocity.

Abstract

We report on an experimental study of the normal impact on a solid surface of a table tennis ball that rotates around its linear velocity vector. We observe that the ratio of the reflected velocity to the incident velocity does not depend on the initial spin. In contrast, the reflected spin depends not only on the incident spin but also on the incident velocity. The experimental results, which reveal the tricky role played by the friction in the region of contact, are accounted for by simple theoretical arguments.