Hello, I'm currently a junior in high school and had an interesting idea that relates to my science fair project. If this is possible, it could create something truly innovative. My question: Is there a way for a high mass armature's (projectile carrying device) kinetic energy to be transferred to a projectile, have the armature decelerate, and have the low mass projectile accelerate? The projectile and the armature are both moving at the same speed initially. Let's say that the mass of the armature is 4kg and the mass of the projectile is 1kg just for simplicity's sake. My goal is to have the combined velocity of both the armature and the projectile be higher after the exchange of energy than before the exchange. Because momentum is conserved in a collision, the increase of velocity of the lower mass object should increase more than the velocity of the higher mass object decreases. Is there even a technology that can facilitate this exchange of kinetic energy? The higher the efficiency of the exchange, the better.