Medium MCQ +4 / -1 PYQ · JEE Mains 2021

A body at rest is moved along a horizontal straight line by a machine delivering a constant power. The distance moved by the body in time 't' is proportional to :

  1. A ${t^{{3 \over 2}}}$ Correct answer
  2. B ${t^{{1 \over 2}}}$
  3. C ${t^{{1 \over 4}}}$
  4. D ${t^{{3 \over 4}}}$

Solution

P = constant<br><br>${1 \over 2}$mv<sup>2</sup> = Pt<br><br>$\Rightarrow$ v $\propto$ $\sqrt t$<br><br>${{dx} \over {dt}} = C\sqrt t$ [C = constant]<br><br>by integration.<br><br>$x = C{{{t^{{1 \over 2} + 1}}} \over {{1 \over 2} + 1}}$<br><br>$x \propto {t^{3/2}}$

About this question

Subject: Physics · Chapter: Work, Energy and Power · Topic: Work Done by a Force

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