The coefficient of restitution describes the elasticity of a collision:
- 1 = perfectly elastic, kinetic energy is conserved
- 0 = perfectly inelastic, the objects move at the same speed post impact
However, COR values > 1 and < 0 are also physically meaningful:
- COR > 1, a collision where the impact adds energy (e.g. an explosion)
- COR < 0, a partial collision where the objects partially pass through each other. Say, like this:
Are there colloquial terms that characterize these types of collisions? Perhaps explosion does work well enough for the first case, but I can't think of anything that adequately describes the apple case.
(If inelastic is defined as COR != 1 it's probably broad enough but likely not very illuminating in practice.)