Coefficient of restitution
= Coefficient of restitution
{title2=$e=\frac{\text{normal separation speed}}{\text{normal approach speed}}$}
{wiki}
The restitution law applies to velocities of the actual contact points, including any rotational velocities of rigid bodies. A perfectly <elastic collision> has $e=1$; $e=0$ gives zero immediate normal separation speed, but does not by itself require all parts of colliding bodies to share the same velocity.
// Target: classical-mechanics.bigb