Which fundamental principle explains why an ice skater spins faster when pulling their arms inward toward their body axis?

💡 Solution & Explanation

Angular momentum is conserved when no external torque acts on a rotating system, meaning the product of the moment of inertia and angular velocity remains constant. When an ice skater pulls their arms inward, their moment of inertia decreases, which compels their rotational speed to increase to keep angular momentum unchanged. Other principles like linear momentum or Archimedes' principle govern translational motion and buoyancy respectively.