In gym class we are currently in the Floor Hockey unit, and it has me thinking about all the physics behind hockey, both ice and floor hockey. First of all, in ice hockey, skating is an important feature. The coefficient of kinetic friction between skates and the ice is very, very low, it almost acts as a friction less surface. As result, when hockey players exert a force on the ground to accelerate themselves forward, the only way to stop in time is to turn the skates sideways and let the sharp skates dig in the ice to create a strong force of friction. For similar reasons, when a puck is shot, it will not slow down unless acted on by another force (usually another player, or the wall). Finally, why do goalies where so much padding? The reason is because a goalie is expected to save shots fired at them up to 150 mph. If they stop it, it will of coarse result in a very high impulse over a short period of time and therefore deliver a strong force to the goalie. For protection, pads are worn to decrease the change in momentum of the puck.