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MHT CET202019 Oct 2020Morning ShiftPhysicsRotational MotionActual

A particle executes uniform circular motion with angular momentum 'L'. Its rotational kinetic energy becomes half, when the angular frequency is doubled. Its new angular momentum is

Options

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

Correct answer

D. L 4

Step-by-step solution

(B) K = 1 2 I ², ~L = I K ^ = 1 2 I ^ ^ 2 , ^ =2 K ^ = 1 2 I ^ (2 )², ~K ^ = K 2 1 2 ( 1 2 I ² )= 1 2 I ^ (2 )² I ^ = I 8 ~L ^ = I ^ ^ = I 8 2 = I 4 = L 4

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