Why Pucks
Fly
Why do pucks lift off
the ice when a slapshot is taken?
Even though for simplicities sake the
calculations were done earlier assuming no
friction, when a puck slides across the ice
there is friction and this causes heat.
This is important because that little heat melts
some of the ice into water. This water
creates a kind of suction on the puck keeping it
on the ice. When a puck is shot by a
slapshot the bottom of the blade of the stick
breaks the seal by lifting up slightly on the
puck.
The curve of the blade causes the puck to start
spinning creating the same Bernoulli effect that
a Frisbee does to fly. Most of hockey
stick blades are curved either to the right or
the left. when a puck is shot it travels
along this curve. The blade of a hockey
stick is also covered with a cloth like tape
that allows for better handling of the puck and
adds an additional layer of protection. Because
this tape is only about 3/4 in. wide it is
wrapped around the blade. this creates
ridges helping to make the puck spin as it comes
off the stick.
The Bernoulli effect is the effect of
lift. when a wing crates lift it is more
accurate to say that it creates the lack of
force holding it on the ground. In essence
the spinning and round nature of a hockey puck
force the air to move slightly faster over the
top of the puck than the bottom. This
faster moving air creates a low pressure
spot allowing the puck to rise more. As
the airspeed around the the puck starts to
equalize the puck's rise slows until it reaches
the top of the parabolic arc and starts to fall
back to the ice.
What does the flight path look like?
The flight path of a hockey puck is the same
simple parabolic arc that is created by type of
projectile motion. If the angle that the
puck leaves the ice, the velocity, and the
acceleration are known then it is possible to
predict how far away the puck will land.
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