A railroad car of mass 2.54 104 kg, is moving with a speed of 3.91 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 1.96 m/s.
(a) What is the speed of the four cars after the collision?
m/s
(b) How much energy is transformed into internal energy in the collision?
kJ