Question

Can you tell from the coefficient of restitution whether a collision has added kinetic energy to a system, taken some away, or left the system's kinetic energy unchanged?

Answer 1

For an inelastic collision where coefficient of restitution,e, is equal to 0, the momentum is conserved but not the kinetic energy. So, there is addition or elimination of kinetic energy.

On the otherhand, when e = 1, like for an elastic collision, kinetic energy and momentum is conserved. Thus, the system's kinetic energy is unchanged.