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LESTER HOLT, Anchor: The stakes are high for the snowboarders
in Vancouver, as they try to master new tricks to unseat the star of Torino,
American Shaun White.
But to get "max air" off the half-pipe without losing their
balance, they might want to check out this experiment that Paul Doherty,
a physicist funded by the National Science Foundation,
has cooked up using a skateboard and a glass of water.
HOLT: Ever since snowboarding made its Olympics debut twelve years ago,
it's taken off worldwide.
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INTERVIEWER: So tell me in Italian, "I'm going snowboarding."
SILVIA ZUCCIATTI, Burton Snowboard School: [in Italian] I'm going
snowboarding.
HOLT: The lingo that American snowboarders use might still sound
like a foreign language to some.
HANNAH TETER, Gold Medalist: I dropped into a crippler to a back
three, and after that I was like, "Whoo whoo!"
HOLT: But the science that these boarders use to do tricks on the
half-pipe couldn't be simpler: The Laws of Gravity.
Building Speed.
And especially balance.
At the Exploratorium Museum in San Francisco,
Senior Staff Scientist Paul Doherty knows a thing or two about
the physics of snowboarding.
DR. PAUL DOHERTY, The Exploratorium: What really interests me about the
half pipe is it's an example of dynamic balance.
The snowboarder has to realize that when they're in motion in this half
pipe, the balance that they keep is quite different than if they were
standing still on a steep slope.
HOLT: He even created a model to show how snowboarders can keep their
balance in the half-pipe, stay upright, without taking a spill.
DOHERTY: If I'm building up my motion in the half pipe,
back and forth, I can go all the way up to the rim and the water stays
level in the glass.
A snowboarder has to remember that when they're in the half pipe.
They have to feel not only gravity straight down,
but the forces of the snow on them, which change angle as they move.
HOLT: As gravity pulls snowboarders down the half pipe, they gain speed.
But at the very same time, they're being pushed against the sides of
the half pipe by contact forces from the surface of the snow.
DOHERTY: That snowboarder feels like they're being crushed against the surface.
HOLT: Even 2006 Gold Medalist Sean White has felt the power that
friction can exert on his board.
SHAUN WHITE, U.S. Olympic Snowboarder: There's actually like g-force when you're
going up, and it's sucking you against the wall.
HOLT: Snowboarders push back against these G-Forces--and build more
speed--by "pumping" their legs up and down.
KEVIN PEARCE, snowboarder: Every time you see someone in the
half-pipe who's going fast and big, they're pumping.
ANNOUNCER: "She lands so high, and is able to pump as hard as she can,
across the flatbottom."
HOLT: By standing up against those extra forces in the curve,
snowboarders add to their kinetic energy, the energy of motion.
And that gives them the speed they need to get air.
KEVIN PEARCE, U.S. Snowboarding Team: So the whole idea is to go as fast
as possible, because the faster you go, the higher you go.
And the higher you go, the more points you get and the better tricks you can do.
HOLT: One more factor in achieving maximum speed is the height
of the half-pipe.
The taller the pipe, the more gravitational energy a snowboarder
stores at the top.
Potential energy: that's what gives matter the potential to move.
When a snowboarder launches down the ramp,
that potential energy gets converted into kinetic energy.
DR. DEBORAH KING, Ithaca College: When they take off the ground,
they are generating a lot of velocity, so they have kinetic energy.
As they go up in the air, gravity is slowing them down,
so they are actually losing kinetic energy and it's being converted
to potential energy.
When they are at the top of their jump,
and they are at their highest, they have the most potential energy.
HOLT: That potential energy will come in handy in Vancouver,
where the new in-ground "superpipe" created for the 2010 Olympics will
be the biggest one ever, rising 22 feet high.
At that height, we'll see some awesome tricks,
and the boarders will have more time to hang out ...
in the air.