A 3.5kg block moving at 2.0 m/s toward the west on a frictionless surface has an elastic head-on collision with a second 1.1kg block traveling east at 3.0 m/s.
1. Decide the kinetic energy of the first block after the collision
2. Decide the kinetic energy of the first block before the collision
3. Determine the final velocity of the first block. Suppose due east direction is positive.