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JEE Main 2005 (AIEEE) · Power

Power question from JEE Main 2005 (AIEEE)

Q47JEE Main 2005 · AIEEEEasy

Power

A body of mass mm is accelerated uniformly from rest to a speed vv in a time T.T. The instantaneous power delivered to the body as a function of time is given by

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Answer: (b)

  1. Uniform acceleration a=vTa = \dfrac{v}{T}, so force F=mvTF = \dfrac{mv}{T}.
  2. Speed at time tt: v(t)=vTtv(t) = \dfrac{v}{T}t.
  3. P=F v(t)=mv2T2 tP = F\,v(t) = \dfrac{mv^2}{T^2}\,t
  4. So the answer is (b).
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