Inelastic collision and the Hertz theory of impact

Abstract

The area, A, and the duration of contact, T, have been measured as a function of impact speed, U, for balls striking a flat surface. The balls lost about 40% of their kinetic energy over the range of speeds studied, but, surprisingly, the results for A(U) and T(U) appear to be consistent with Hertz’s elastic theory of impact. Possible reasons are discussed for this unexpected behavior.