Elastic And Non-elastic Collisions In A`level Physics

Elastic Collisions.

A collision is described as elastic if the Kinetic Energy (KE) is conserved.

ie. KE before the collision = KE after the collision

Inelastic Collisions.

A collision is described as inelastic if the Kinetic energy is NOT conserved.

Make sure you don`t forget that in all collisions Linear Momentum must always be conserved.

Let us consider the following situation.

A fairground bumper car (A) of mass 300kg moving at 5m/s drives into the back of a second bumper car (B)

Bumper car B has a mass of 300kg and before the collision was moving at 1m/s in the same direction as bumper car A.

After the collision bumper car A moves at 2m/s and bumper car B moves at 4m/s.

You should be able to do the following,

1. Use the formula Momentum = mass x velocity to show that the total momentum of the bumper cars before the collision is equal to the total momentum of the bumper cars after the collision.

For both the Momentum = 1800 kgm/s

2. Use the Kinetic Energy formula to show that the total KE before the collision is 3900J

3. Use the Kinetic Energy formula to show that the total KE after the collision is 3000J

4. make a comment explaining how you know that this collision was an inelastic collision!

Good luck.