Two bumper cars in an amusement park ride collide elastically as one approaches the other directly from

Question:

Two bumper cars in an amusement park ride collide elastically as one approaches the other directly from the rear (Fig. 7-43). Car A has a mass of 435 kg and car B 495 kg, owing to differences in passenger mass. If car A approaches at 4.50m/s and car B is moving at 3.70 m/s, calculate

(a) Their velocities after the collision,

(b) The change in momentum of each.