A railroad car of mass 2500 kg moving at 5.00 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 2.20 m/s. (a) What is the speed of the three coupled cars after the collision?

Question

A railroad car of mass 2500 kg moving at 5.00 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 2.20 m/s.  (a) What is the speed of the three coupled cars after the collision?

bobpursley · Answer

momentum before= momentum after m*5+2*m*2.2=3mV solve for V