©
Dr. Steve Rapp,
2004
Elastic Collisions
u
A vector diagram shows the momenta of the
balls before and after collision.
MbV’b
MrV’r
MbVb
Since the masses are equal
Vb
2
= V’b
2
+ V’r
2
.
When two balls of equal mass strike one another
(one is at rest), the two balls move away from one
another at right angles.