Question

A cannon on a stationery railway truck fires a shell of mass 5 kg with a velocity of 240 m.s -1. The mass of the cannon is 600kg. The cannon recoils and moves back on the rails and collides with a stationery truck of mass 400 kg. The velocity of the cannon after the collision is 0.8 m.s -1. With what velocity does the second truck move after the collision.