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⚛️ Physics  ·  System of Particles and Rotational Motion  ·  NEET & JEE

When a spinning ice skater pulls in her arms, her angular velocity:

Answer: Increases.

  • A Increases
  • B Decreases
  • C Stays the same
  • D Becomes zero

Correct answer: A. Increases

Explanation: Angular momentum L = Iω is conserved. Pulling arms in reduces I, so ω must increase to keep L constant.

axis OPr⊥Fττ = r⊥ × F = r × F × sinθ

Torque about axis O equals the force F multiplied by the perpendicular distance r⊥ from the axis to the line of action of the force, producing rotation.

Concept context

Moment of inertia, torque, angular momentum, rolling motion. Very high JEE weightage.

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