Example problems from class:
1.Two billiard balls move toward one another. The balls have identical masses and
assume that the collision is elastic. If the initial velocities of the balls are +3 m/s
and -2 m/s, what is the velocity of each ball after the collision?
2.Find the final velocity of the two balls if the ball with the initial velocity -2 m/s
has a mass equal to half the ball with the initial velocity of +3 m/s. (still an elastic
collision)