Transcript The Physics of Hockey

The Physics of Hockey
By Ryan D. Smith (rds5164)
Physics 001, Section 001
Instructor: John Hopkins
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.
Newton’s First Law:
Stationary Goalie
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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
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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)
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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
Newton’s Second Law:
Body-Checking
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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
Newton’s Third Law:
Slap Shots & Skating
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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
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The amount of force a player generates
when firing a shot is equivalent to the
force that the puck will return to the shottaker (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
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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
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.
Reference
• http://sharksfan14.tripod.com/id5.html
• Images:
– http://t0.gstatic.com/images?q=tbn:GcJoCmZDiZKfG
M:http://tenderslounge.files.wordpress.com/2008/05/p
elle-lindbergh.jpg
– http://community.post-gazette.com/resizedimage.ashx/__size/500x400/__key/CommunityServer.
Components.PostAttachments/00.00.22.66.33/dianap
enguins1007f.jpg
– http://oldmansporch.files.wordpress.com/2009/11/jaro
me-iginla-scores-goal-365.jpg
– http://news.globaltv.com/sports/Oilers+come+back+C
oyotes+howl/2408334/2410759.bin?size=sw380nws