# Why is angular momentum important in figure skating?

Oct 4, 2015

Angular momentum can be used to explain why figure skaters move they way they move in a performance.

#### Explanation:

Angular momentum is the counterpart of linear momentum. Whereas linear momentum is dependent on mass, angular momentum is dependent on "angular mass" (momentum of inertia).

Angular momentum is defined as:

$L = I \cdot \omega$

By a proper relations manipulations:

$L = r \cdot m \cdot v$

Where: L -linear momentum; m - mass; v - linear speed.

Since momentum is conserved, if we change the radius, i.e. r, and we are talking about motion is speed much smaller than the speed of light, we have that the linear speed must increase to compensate. This is the principle applied by them, bearing in mind that most of the moves are spinning around.

If you have already been in a lab of physics, there is a famous chair, in which someone rotates you, and you must close your arms, move your legs and arms inwards, you experience an increase of speed, until you bring your legs and arms again to an outward position.

See the movie: , or the others, called Cutting edge, you have several moves.

See the Gyroscope, it is a systems that remain upward due to angular speed. see also Top (a kids toy that stays moving in circle). 