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MHT CET202120 Sep 2021Evening ShiftPhysicsRotational MotionActual

Two bodies rotate with kinetic energies ' E₁ ' and ' E₂ '. Moment of inertia about their axis of rotation are ' I₁ ' and ' I₂ '. If I₁= I₂ 3 and E ₁=27 E ₂ , then the ratio of angular momenta ' L ₁ ' to ' L ₂ ' is

Options

  1. A1: 3
  2. B3: 1
  3. C1: 1
  4. D2: 1

Correct answer

B. 3: 1

Step-by-step solution

aligned & E ₁= 1 2 I ₁ ₁^2 & E ₂= 1 2 I ₂ ₂^2= 1 2 (3 I ₁ ) ₂^2= 3 2 I ₁ ₂^2 [ I ₂=3 I ₁ ] & E ₁=27 E ₂ & 1 2 I ₁ ₁^2= 81 2 I ₁ ₂^2 & ₁=9 ₂ & L ₁ ~L ₂ = I ₁ ₁ I ₂ ₂ = I ₁ 9 ₂ 3 I ₁ ₂ =3 aligned

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