Two moving billiard balls, each with a mass of M, undergo an elastic collision. Immediately before the collision, ball A is moving east at 2 m/s and ball B is moving east at 4 m/s. a. In terms of M, what is the total momentum (magnitude and direction) immediately before the collision?

b. The final momentum, M(vA, f + vB, f), must equal the initial momentum. If the final velocity of ball A increases to 4 m/s east because of the collision, what is the final momentum of ball B?

c. For each ball, compare the final momentum of the ball to the initial momentum of the other ball. These results are typical of head-on elastic collisions. What generalization about head-on elastic collisions can you make?