A railroad car of mass 3.50*10^4 kg moving at 3.30 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 1.20 m/s.

A railroad car of mass 3.50 x 104 kg moving at 3.30 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 1.20 m/s. (a) What is the speed of the three coupled cars after the collision? 1.9 y m/s (b) How much kinetic energy is lost in the collision? x J