A figure skater spinning at 2 rad/s pulls her arms close to her body. What happens to her spin speed?
She doesn't push off the ice again. No external force is applied. Yet something remarkable happens...
The Challenge: Predict the Spin Speed
The skater starts with a moment of inertia I = 3 kg*m^2 (arms extended). When she pulls her arms in, her moment of inertia drops to I = 1 kg*m^2. No external torques act on her.
After pulling her arms in, the skater will:
Take a guess! Understanding rotational motion explains everything from figure skating to gyroscopes to spacecraft control.
