Physics
Angular Momentum Conservation in Figure Skating
Quick fact
When a figure skater pulls in their arms, they spin faster; when they stretch out, they spin slower. This is due to the conservation of angular momentum.
Why this is interesting
Have you ever watched a figure skater spin rapidly on one foot, then slow down by extending their arms? How do they control their speed without touching the ice?
Read the full explanation
Understanding Angular Momentum Conservation in Figure Skating
Imagine you're spinning on a chair with your arms stretched out. As you pull them in, you start to spin faster — like a figure skater! This happens because there’s no external force acting on you, so your total rotational motion stays the same. Your body changes shape, but your spin speed adjusts accordingly.
A deeper explanation
Angular momentum is conserved when no external torque acts on an object. In figure skating, when a skater pulls their arms in, they reduce their moment of inertia (resistance to rotation), which causes their rotational speed to increase to keep angular momentum constant. Conversely, when they stretch out, the moment of inertia increases, and their spin slows down. This principle allows skaters to perform elegant, controlled spins during performances.