Sports
Conservation of Angular Momentum in Skating Spins
Quick fact
A skater can increase their rotation speed by up to 5 times simply by pulling their limbs closer to their body.
Why this is interesting
Ever wondered why figure skaters spin faster when they pull their arms in? It's all about a fundamental physics principle that keeps things spinning!
Read the full explanation
Understanding Conservation of Angular Momentum in Skating Spins
Imagine holding a spinning toy. If you pull your arms in, the toy spins faster — this is because angular momentum stays constant unless an external force acts on it. Skaters use this principle: when they bring their arms and legs close to their body during a spin, their moment of inertia decreases, so they spin faster to conserve angular momentum.
A deeper explanation
Angular momentum is conserved in the absence of external torque. When a skater pulls their limbs inward, their moment of inertia (resistance to rotational change) decreases, and to maintain constant angular momentum, their rotational speed increases. This principle is key to mastering precise spins and maneuvers in figure skating.