A railroad car of mass 2.51 104 kilogram, is moving with a speed of 3.80 m/s. It collides and couples with three other coupled railroad cars, each of the similar mass as the single car and moving in the same direction with an initial speed of 1.90 m/s.
(a) Determine the speed of the four cars after the collision?
m/s
(b) Find how much energy is transformed into internal energy in the collision?
kJ