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MHT CET202121 Sep 2021Morning ShiftPhysicsRotational MotionActual

The moment of inertia of a body about a given axis is 1.2 ~kg m ^2 . Initially the body is at rest. In order to produce rotational kinetic energy of 1500 ~J , an angular acceleration of 25 rad / s ^2 must be applied about an axis for a time duration of

Options

  1. A8 ~s
  2. B2 ~s
  3. C4 ~s
  4. D1 ~s

Correct answer

B. 2 ~s

Step-by-step solution

aligned & I =1.2 ~kg - m ^2, ~K . E .=1500 ~J , =25 rad / s ^2 & K.E. = 1 2 I ^2 & 1500= 1 2 1.2 ^2 & =50 rad / s & = ₀+ t & 50=0+25 t =25 t & t =2 ~s aligned

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