# The Physics Behind Figure Skating

#### Ariel Ellison - PHYS 211 F02 - Fall 2014

The sport of figure skating is well known for its graceful execution thanks to iconic Olympic Figure Skaters like Michelle Kwan and Peggy Fleming, but itâ€™s easy for viewers to overlook the amount of strength, power and perseverance it takes to be a successful figure skater. In the pages following we will take a look at some of the physics hiding behind these elegant athletes.

##### Center of Mass

Center of Mass is probably the single most important thing in understanding how athletes such as figure skaters, gymnasts, skiers, etc. are able to do the things that they do. Simply put, center of mass is the mass weighted center of an object (or person). On a human body, the center of mass is generally located near the belly button or right above the hip area. The location of a figure skaters center of mass during any type of skating movement can greatly effect the stability of the skater. The stability of an object will always be greater if the objects center of mass is located over its base of support. This fact is why beginning skaters or skiers are always told to bend their knees and do their best to keep their feet (base of support) located directly beneath them. Center of mass is something that all figure skaters need to be aware of, especially when executing advanced movements such as, triple axels or flying camel spins.

##### Projectile Motion

A projectile, such as a ball or figure skater, is an object that moves in two dimensions (horizontal and vertical) along a parabolic trajectory curve solely under the influence of gravity. In figure skating, projectile motion can be most readily seen when a skater performs a large jump where the parabolic trajectory is most noticeable. Although not as clear to point out, projectile motion can occur during small footwork steps or in the entrance of a spin.

Angular Momentum, also known as rotational momentum, can be defined as the amount of rotation an object experiences. It is a vector quantity, meaning it has both a magnitude and a direction, and it depends on the objects moment of inertia and its angular velocity. Angular momentum is essentially the product of the objects moment of inertia and the objects angular velocity. In figure skating, the concept of angular momentum is extremely important in order to complete a successful jump or spin, without it there would be no spinning at all!