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AP EAMCET201823 Apr 2018Morning ShiftPhysicsRotational MotionActual

The moment of inertia of a body about a given axis is 12 ~kg - m ^2 . Initially, the body is at rest. In order to produce a rotational kinetic energy of 15000 ~J , an angular acceleration of 10 rads ⁻² must be applied about that axis for a duration of

Options

  1. A2 s
  2. B4 s
  3. C10 s
  4. D5 s

Correct answer

D. 5 s

Step-by-step solution

Given, moment of inertia, I=12 ~kg - m ^2 Rotational kinetic energy, E_k= 1 2 I ^2 15000 ~J = 1 2 12 ^2 So, = 30000 12 = 2500 =50 rad / s Angular acceleration, =10 rad / s ^2 As = t So, time = = 50 10 =5 ~s

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