A railroad car of mass 24000 kg is moving with a speed of4.03m/s. It collides and couples with three other coupled railroadcars, each of the same mass as the single car and moving in thesame direction with an initial speed of 2.02m/s. The initial speed of the four cars after the collision is 2.5 m/s. How much energy is transformed into internal energy in the collision?