Experiments on impact

This paper, which describes the continuation of a research upon the impact of soft metallic bodies, contains the results of four investigations, as follows: (1) Impact of equal spheres for low values of the velocity of approach ν. The duration of contact is found to vary inversely as νfraction one-fifth, while the coefficients of restitution e in the same cases are found to be unity for all speeds below a value characteristic of each material, as though the metals were perfectly elastic for smaller speeds. (2) The effect of duration of contact upon the size of the permanent deformations. No effect was observed. (3) The variation of duration of contact t with mass of sphere at high speeds of approach. Within the limits of experimental error, t varies as the square root of the mass, as theory predicts. (4) The impact of crossed cylinders. No important new phenomena are found.