Need some help in friction, plz help!?

a trolly weighing 10000 kg stands on rails. a cannon weighing 5000 kg is fastened on it frm which a shell is fired along the rails. the shell weighs 100kg and its initial velocity with respect to the cannon is 500m/s. find the distance through which the trolly moves after the shot if it is moving with a velocity of 5m/s and the shell is fired in the opposite direction. the coefficient of friction between the trolly and the rails is 0.002.