Football seems pretty stupid to me. Athletes line up across from eachother, then run at eachother as fast as they can. However, football is my favorite sport to watch. There is alot of large forces coliding in football. Every colision can be related back to physics. The force of anything is determind by its mass and acceleration. The larger the mass of an athlete and the more acceleration an athelete has the larger the force the athlete can produce. NFL players can produce large forces on eachother. This leads to big hits and head injuries.