Professional baseball pitcher throws a 0.145kg baseball with a velocity of 40m/s north. The ball is batted to the pitcher with a velocity of 49m/s south. What is the magnitude of the change in the balls momentum? A, 1.305kg Xm/s B. 1.3 kgXm/s C. 12.905 kg Xm/s D. 13 kg Xm/s 2. A billard ball collides with a second identical ball in an elastic head on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision? A. Unchanged B two times as great C four times as great D one fourth as great