# Elastic Collisions in One Dimension

Elastic Collisions in One Dimension

As we discussed , everyday collisions are inelastic but we can approximate
some of them as being elastic; that is, we can approximate that the total kinetic energy of the colliding bodies is conserved and is not transferred to other forms of energy.

1. Equal masses which we might call a pool player’s result. It predicts that after a head-on collision of bodies with equal masses, body I (initially moving) stops dead in its tracks and body.

2. A massive target , a massive target means that .For example, we might fire a golf ball at a cannonball.

3. A massive projectile This is the opposite case. This time, we fire a cannonball at a golf ball.

You may wonder. Why twice the speed? As a starting point in thinking about the matter, recall the collision described by , in which the velocity of the incident light body (the golf ball) changed from +V to -v, a velocity change of . The same change in velocity (but now from zero to 2v) occurs in this example.