The elasticity of the collision is related to the ratio of the relative velocities of the two colliding objects after and before the collision:
k = (v2f - v1f) / (v1i - v2i)
The elasticity is related to the type of collision as follows:
| Type of Collision | Elasticity |
|---|---|
| Super-elastic | k > 1 |
| Elastic | k = 1 |
| Inelastic | k < 1 |
| Completely inelastic | k = 0 |