The sliders in the simulation set the mass and initial velocity of the two carts, as well as the elasticity of the collision.

The elasticity k is defined as the ratio of the relative velocities of the two colliding objects after and before the collision:

k = (v_2f - v_1f) / (v_1i - v_2i)

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

Here are some things to think about when using the simulation:

• The total momentum before and after a collision should always be the same.
• The total kinetic energy before and after a collision is only the same for an elastic collision.