A railroad car of mass 23200 kg moving at 4.33 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and...

A railroad car of mass 23200 kg moving at 4.33 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 2.63 m/s. What is the speed of the three coupled cars after the collision? Answer in units of m/s.

How much kinetic energy is lost in the collision? Answer in units of J.