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AP EAMCET2002PhysicsRotational Motion

The diameter of a flywheel is 1 ~m . It has a mass of 20 ~kg . It is rotating about its axis with a speed of 120 rotations in one minute. Its angular momentum in kg - m ^2 / s is

Options

  1. A13.4
  2. B31.4
  3. C41.4
  4. D43.4

Correct answer

B. 31.4

Step-by-step solution

aligned & r= 1 2 ~m =0.5 ~m , m=20 ~kg , & n=120 rotation per minute, &=2 rotation per sec. & Angular momentum L=I &= M r^2 2 2 n= 20 (0.5)^2 2 2 3.14 2 &=5 3.14 2=31.4 ~kg - m ^2 / s aligned

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