12) A 16.0 kg canoe moving to the left at 12.0 m/s makes an elastic head-on collision with a 4.00 kg raft moving to the right at 6.00 m/s. After the collision, the raft moves to the left at 22.7 m/s. Disregard any effects of the water. Find the velocity of the canoe after the collision.

13) A 4.0 kg bowling ball sliding to the right at 8.0 m/s has an elastic head-on collision with another 4.0 kg bowling ball initially at rest. The first ball stops after the collision. Find the velocity of the second ball after the collision.

14) A 25 kg bumper car moving to the right at 5.0 m/s overtakes and collides elastically with a 35 kg bumper car moving to the right. After the collision, the 25 kg bumper car slows to 1.5 m/s to the right, and the 35 kg bumper car moves at 4.5 m/s to the right. Find the velocity of the 35 kg bumper car before the collision.