Sports
Conservation of Angular Momentum in Figure Skating
Quick fact
A skater can increase their rotation speed by up to four times simply by bringing their arms closer to their body.
Why this is interesting
Have you ever watched a figure skater spin faster by pulling their arms in? It’s not magic—it’s physics.
Read the full explanation
Understanding Conservation of Angular Momentum in Figure Skating
Angular momentum is the measure of rotational motion. When a skater pulls their arms in, they reduce their moment of inertia, which causes them to spin faster to conserve angular momentum. Imagine spinning on a chair with your arms out—when you pull them in, you start spinning more quickly!
A deeper explanation
The conservation of angular momentum states that if no external torque acts on an object, its total angular momentum remains constant. In figure skating, when a skater pulls their limbs closer to the axis of rotation, they decrease their moment of inertia, which causes an increase in rotational speed to keep angular momentum conserved. This principle is fundamental to understanding how objects rotate and change their motion under constraint.