Situation 4. A railroad car of mass 2.50x10^4 kg is moving with a speed of 4.00 m/s. It collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 2.00 m/s. What is the speed of the four cars after the collision? How much mechanical energy is lost in the collision?

Situation 4. A railroad car of mass 2.50x10^4 kg is moving with a speed of 4.00 m/s. It collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 2.00 m/s. What is the speed of the four cars after the collision? How much mechanical energy is lost in the collision?