The Physics of Hockey

1. The Physics of Hockey By Ryan D. Smith (rds5164) Physics 001, Section 001 Instructor: John Hopkins

2. Overview Hockey is a sport whose actions accurately depict each of Isaac Newton’s Laws of Motion. For a game that can be chaotic in the eyes of many fans, so many little actions on the ice can affect the result of the game. Many of these little actions come as a result of one of the Newtonian Laws.

3. Newton’s First Law: Stationary Goalie States “An object at rest, or in uniform straight line motion, will remain at rest, or in uniform straight line motion, unless acted upon by a net external force.” In hockey, a good example: a goalie standing still awaiting the shot In reality, a goalie will be moving to try to stop the puck However, when still, the goalie is not affected by any outside forces until the puck, or another player, comes into contact with him Another example: the puck sliding along the ice (if we ignored friction) Puck will tend to stay in a constant motion along the ice While friction is evident, it is a low force of friction when compared to other surfaces If there were no friction, the puck would keep traveling until it hit the boards, was played by a stick, or was affected by an external force in another fashion

4. Newton’s Second Law: Body-Checking As stated in class, 2nd law states “A net force acting on a body produces on that body, an acceleration that is directly related to the force impressed upon the body and inversely related to the mass of the body. Or, simply stated, Force= Mass x Acceleration 2nd Law deals with collisions, and in hockey, body-checks are a source multiple collisions in a game Bigger players are able to generate, mathematically speaking, bigger-force hits because their masses are obviously greater than the players they are targeting with checks At the same time, though, players who are smaller can still generate as big a check if their acceleration rate upon delivering a check was high, since both mass & acceleration are components of the force of a body-check

5. Newton’s Third Law: Slap Shots & Skating According to Newton, for every action, there is an equal and opposite reaction Hockey examples range from body checks to the puck hitting the net However, two very visual examples are slap shots and skating Slap Shots The amount of force a player generates when firing a shot is equivalent to the force that the puck will return to the shot-taker (this explains the warped bend of a stick on hard shots) If the force the puck returns to the stick is too high, the stick can break Skating When a player skates, the force of his skates against the ice is equal to the force the ice returns to the skate blades This can be seen when a player quickly slows, creating a “snow shower” effect

6. Newton’s Importance Without knowing it, Isaac Newton’s laws create the entire basis for the fast-paced excitement of hockey. Literally every type of hockey play involves one of his Laws, and without him, it would be impossible to scientifically explain such a frenetic-paced sport.

7. Reference http://sharksfan14.tripod.com/id5.html Images: http://t0.gstatic.com/images?q=tbn:GcJoCmZDiZKfGM:http://tenderslounge.files.wordpress.com/2008/05/pelle-lindbergh.jpg http://community.post-gazette.com/resized-image.ashx/__size/500x400/__key/CommunityServer.Components.PostAttachments/00.00.22.66.33/dianapenguins1007f.jpg http://oldmansporch.files.wordpress.com/2009/11/jarome-iginla-scores-goal-365.jpg http://news.globaltv.com/sports/Oilers+come+back+Coyotes+howl/2408334/2410759.bin?size=sw380nws