ouch. when physics hits back

This past weekend while at my grandparents’ house, my cousins brought their airsoft guns. So we went to backyard to play with them and shoot some cans and water ballons while we waited for lunch to be ready. Airsoft has a lot to do with physics. The guns which we used were electric and were powered by rechargeable batteries. My uncle said that the batteries power an electric motor that turns a gear box or something which compresses a spring. The tension from the spring is then released, sending the plastic BBs through a chamber and out of the barrel. The tension created in the spring must be pretty immense because those BBs fly right out of those guns! With such small masses, it makes sense that they move so fast. However, a smaller mass leaves the BBs susceptible to wind and stuff which can lower accuracy. So, different masses of BBs are used. But if you think about it, the pellets can’t be that heavy, or else they wouldn’t be able to move quickly or hit far targets, so their amount of KE transferred can’t be that big (E=1/2mv2). This means that BBs aren’t super damaging, when compared to larger paintballs for example. I learned this firsthand when my cousin shot me in the leg. Because of the small mass of the pellet and long distance between me and him and his gun, the shot hurt, but not that much. This makes sense because since the pellets we were using were of a small mass, they had small inertias. And although they were shot at higher velocities than other heavier pellets would be, they also lost speed quickly; therefore minimizing the hurt I felt when the BB finally reached me. The flight and flight path of the pellets also are physics related. When we shot the BBs this weekend, because we were aiming for cans and other things close by, their paths appeared perfectly horizontal. But when shooting the gun at a slightly upward angle the other weekend, I could see the parabolic flight of the pellet. My neighbors own Toys n Joys and my uncle likes to play with the airsoft guns. So the other weekend he brought home an airsoft gun that had this tracking thing so the pellets glowed in the dark! It was a perfectly clear and dark night so we all stopped our football game and told our uncle to get the gun. Standing in his driveway, my uncle aimed the gun kind of upwards and we could see its path clearly...it was parabolic :-) The way the BBs fly is physics too and is at the hand of Bernoulli’s principle—the same principle through which airplanes get lift. Airsoft—more fun thanks to physics.