A railroad car of mass 2.3 x 104 kilogram moving at 4.00 m/s collides and couples with two coupled railroad cars, each of the similar mass as the single car and moving in the similar direction at 1.20 m/s.
(a) Estimate the speed of the three coupled cars after the collision?
m/s
(b) Estimate how much kinetic energy is lost in the collision?
J