E14.A railroad car with a mass of 33000.0 kg collides and couples with a second car of mass 10000 kg that is initially at rest. The first car is moving with a speed of 6.0m/s prior to the collision. If external forces can be ignored, what is the final velocity of the two railroad cars after they couple?

E14.A railroad car with a mass of 33000.0 kg collides and couples with a second car of mass 10000 kg that is initially at rest. The first car is moving with a speed of 6.0m/s prior to the collision. If external forces can be ignored, what is the final velocity of the two railroad cars after they couple?