1. The problem statement, all variables and given/known data N cannonballs each of mass m are fired at velocity V one after another from a cannon of mass M(including balls) lying on a movable carriage initially at rest . what will be the final velocity of cannon after the last ball is fired? 2. Relevant equations Initial total momentum = 0 after the first ball is fired let the recoil velocity of the the cannon be v1 and its mass was then M-m then by the law of conservation of linear momentum (M-m)v1 +mv = 0. Now i am confused. My question is in what respect the velocity of the second ball is becoming v. 3. The attempt at a solution So i can not proceed after that. Please help and remove my confusion.