14. A 10,000 kg box car sits at rest on a train track. A 20,000 kg timber car travels west at 1.5 m/s and collides with the empty box car. At the exact same time, a third train car collides with the other end of the box car. This third car is a 14, 000 kg freight car moving at 4 m/s east. If all three cars stick together