Though we just got to witness the
Olympics this past summer, it should not be forgotten that the Winter Olympics
are just two years away. One of the most popular sports to watch is figure
skating, not just for the beauty of the performances, but for the important
laws of physics that underlie every move the skaters make.
The physics starts with the ice.
One of the main reasons ice is a suitable surface on which to skate is its near
lack of friction on the blades of the skates. The center of ice is made up of
tightly crystallized water molecules, but on the surface, these water molecules
are less tightly packed, forming a nearly liquid, frictionless surface. This
allows the skates to glide along the ice, hardly losing any speed.
In order to glide along the ice,
the skater must first generate a force to push themselves forward. The energy
for this force is stored as chemical potential energy (ATP) in the muscle cells
of the skater’s legs. When the skater extends their leg, pushing against the
ice, this potential energy is converted into kinetic energy and they move
forward.
Spinning is a common move in
figure skating, and viewers are often puzzled at how fast skaters can make
themselves spin without adding any extra pushing. Skaters spin faster because
of conservation of angular momentum. When they start spinning and have their
arms and/or leg extended, the radius of their spin is large. Their angular momentum
is proportional to their radius as well as their speed, so by making their
radius smaller by bringing their limbs toward their center, the speed must
increase to keep momentum conserved.
Catherine Stecyk
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.