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MHT CET202013 Oct 2020Evening ShiftPhysicsRotational MotionActual

A rotating body has angular momentum 'L'. If its frequency of rotation is halved and rotational kinetic energy is doubled, its angular momentum becomes

Options

  1. A2 ~L
  2. BL 4
  3. C4 ~L
  4. DL 2

Correct answer

C. 4 ~L

Step-by-step solution

Kinetic energy k= 1 2 I ² k ₂ k ₁ = I ₂ w ₂² I ₁ ₁² 2= I ₂ I ₁ ( l 2 )² I ₂ I ₁ =8 Angular momentum L = I L ₂ ~L ₁ = I ₂ ₂ I ₁ ₁ =8 1 2 =4 L ₂=4 ~L ₁=4 ~L

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