A figure skater pulls in her arms during a spin. Her moment of inertia decreases. By conservation of L (I × omega), her angular velocity:
AIncreases
BBecomes zero
CDecreases
DStays same
Answer & Solution
Correct answer: A. Increases
L = I × omega is conserved (no external torque). If I decreases, omega must increase proportionally. So she spins faster. Note: KE = (1/2) I omega² also increases — extra energy comes from her muscles doing work to pull arms in.
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