1. The problem statement, all variables and given/known data Hi! Task is to calculate kinetic energy of a projectile and cannon recoil velocity. known data: -mass of antiaircraft cannon: 3t -max horizontal distance: 4km -mass of a projectile 2kg barrels: 2 3. The attempt at a solution Since there is no initial velocity or time or max height given i can't find a way to start this.