Home/
Competitive Exams/
JEE Main & Advanced/
Physics/
Rigid Body Dynamics/
Question 30324
JEE Physics · Medium

Rigid Body Dynamics: Angular Velocity from MOI MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
Angular Velocity from MOIMediumQuestion 30324

Question

A figure skater with I = 4 kg·m² spins at 2 rad/s. She pulls arms in, reducing I to 1 kg·m². New angular speed is:
  1. A
    0.5 rad/s
  2. B
    2 rad/s
  3. C
    8 rad/s
    Correct
  4. D
    16 rad/s

Correct answer

8 rad/s

Explanation

Conservation of angular momentum: I₁ω₁ = I₂ω₂ → 4×2 = 1×ω₂ → ω₂ = 8 rad/s.

Review Rigid Body Dynamics notesStart timed chapter practice