A cart of mass M with magnets at an initial height H rolls down a inclined plane with a magnetic stopper at its end.

A cart of mass M with magnets at an initial height H rolls down a inclined plane with a magnetic stopper at its end.

As the cart comes near the magnetic stopper it rebounds up the inclined plane to a maximum rebound height of Hr.

Case 1: Friction is negligible

Case 2: Friction is not negligible

Please explain whether each case is an elastic or inelastic collision. Please also use specific quantitative terms.