Physics of Figure Skating

1. Brandon Ng 3o3(03) Physics of Figure Skating

2. Introduction • Also known as Artistic Skating • Olympic sport • Perform spins,jumps and intricate footwork on ice Watch an example of figure skating here 2010 Winter Olympics Champion : Kim Yuna

3. Disciplines • Singles • Pair skating • Ice dancing • Synchronized skating • Adagio skating • A form of pair skating • Acrobatic skating • Combination of circus arts, artistic gymnastics skills • Special figures • Elaborate original designs on ice

4. Skates • Made of many layers of leather • Very stiff to provide ankle support • Toe picks on the front of blade • Used for certain jumps • Blades are sharp to reduce friction, increasing speed • Newton’s law of inertia

5. Science • Ice is not slippery • When skating, one is skating on water in its liquid form • Ice melts when pressure is applied to it • The greater the pressure on a substance, the lower its freezing point

6. Science • A person’s weight is unable to melt ice under them • However, the sharp skate blade of the ice skates puts the weight of the skater on a small area • Allows skater to glide on a layer of water between the blade and the ice

7. Wonders • Travelling at speeds around 20mph • Completing four revolutions in the air • Land on one leg • Unable to defy gravity or laws of physics • Most people can barely jump high enough to make one revolution without touching the ground

8. Concepts • Torque • Force that leads to rotation • Linear motion • Motion along a straight line • Angular momentum • A conserved vector quantity that can be used to describe the overall state of a physical system • Vorticity • A concept describing horizontal rotation In the atmosphere

9. Vorticity • Skate moves without falling down • Angular momentum helps stabilize the moving body, just like someone riding a bicycle • Skaters spread their arms then bring their hands closer to their bodies • Causing a large moment of inertia • Speed of spinning increases

10. Torque • Spinning is also dependent on torque • Force must be applied some distance from the axis of rotation • ie. If I push a stationary person’s arms, he can spin, but if I push the middle of his body, he will barely move • Force is achieved by pushing the ice • Newton’s law of action-reaction forces • Multiple spins are accomplished with the result from the torque created by turning of one’s skates as one pushes off the ice

11. Torque • The larger or further the force is from the axis of rotation, the larger the torque • The larger the torque, the greater the angular momentum, the more spins made Some skaters can reach rotation speeds of 7 revolutions during a jump, 420 revolutions per minute!

12. Speed and Landing • Rotational speed increased by pulling in their hands closer to body • Reduces air resistance • Streches out their hands and legs for stability while landing Skaters can produce extreme angular momentum at take-off, that they might not be physically strong enough to counteract the G-forces experienced during the rotation. The G-force felt by the arms during a jump or spin may exceed 4Gs!

13. References • http://goldsea.com/810/27sp-kim.html • http://en.wikipedia.org/wiki/Figure_skating#Disciplines • http://www.livescience.com/culture/phsyics-of-figure-skating-100216.html • http://weblogs.cltv.com/features/health/livinghealthy/2010/01/skate-your-way-to-health-rockf.html • http://www.stuffintheair.com/the-physics-of-ice-skating.html • http://en.wikipedia.org/wiki/Angular_momentum#Definition • http://btc.montana.edu/olympics/physbio/biomechanics/cam02.html • http://btc.montana.edu/olympics/physbio/biomechanics/cam03.html • http://www.helium.com/items/197024-the-science-behind-ice-skating • http://www.fouldsy.com/2007/04/