Conservation Collisions

Conservation of Linear Momentum The change in momentum of a system is equal to the impulse put on the system.

Conservation of Linear Momentum For example: Jeff Bagwell hits a baseball… Initially

Conservation of Linear Momentum For example: Jeff Bagwell hits a baseball… During hit

Conservation of Linear Momentum For example: Jeff Bagwell hits a baseball… Finally

Two types of collisions Elastic: The objects do not stick together or change shape. Momentum and kinetic energy are conserved. Inelastic: The objects do stick together and/or change shape. Only momentum is conserved!

Example of an elastic collision The cue ball hits two billiard balls initially at rest on a billiard table. Assume that the cue ball stops after hitting the other balls. What is the final velocity of the red and blue ball? y θ x

y θ x

y θ x

y θ x We have three equations and four unknowns. We cannot solve this problem without more information. You will usually be given the speed or angle of one of the balls.