text: a bullet is fired from a gun.which will have greater kinetic energy,the bullet or the gun?give reason.?   the bullet has much higher kinetic energy than the gun. the bullet and the gun will have the same momentum but the bullet has more energy. (and a good thing for the shooter!) kinetic energy is calculated using the mass of the object and the square of the velocity, while momentum is calculated using the mass of the object and the velocity.     if the bullet and the gun were equal in weight they'd have the same energy and the same momentum - and the shooter would have an injured hand.