physics
posted by sand .
A 3.12 kg bowling ball traveling at 15.3 m/s to the right collides with a 2.15 kg bocce ball traveling at 7.52 m/s to the right. The final velocity of the bowling ball is 2.33 m/s to the left.
Determine the final velocity of the bocce ball. What is the magnitude of the force experienced by the balls if the collision lasts 533 ms? Was the collision elastic?

Apply conservation of momentum in one direction to get the final velocity of the bocce ball.
Divide the momentum change magnitude of either ball by 0.533 to get the average force magnitude.
Add up initial and final total kinetic energies. If they are equal, the collision was elastic.