Direct and Oblique Impact

(4) The coefficient of restitution, as in the case of direct central impact, is the positive ratio of the recovery impulse to the deformation impulse. Hence, like in the case of direct impact,

Once four final velocity components are found, the angles of the figure may be easily determined.

An example:Two ball of the same size and mass collide with the velocities of approach shown. For a coefficient restitution of 0.8, what are the final velocities after they part?