NEET Sample Paper NEET Sample Test Paper-17

  • question_answer
    A body is moved along a straight line by a machine delivering constant power. The distance moved by  the body in time t is proportional to

    A) \[{{t}^{\frac{1}{2}}}\]                               

    B) \[{{t}^{\frac{3}{4}}}\]                               

    C) \[{{t}^{\frac{3}{2}}}\]                               

    D) \[{{t}^{2}}\]   

    Correct Answer: C

    Solution :

    \[P=Fv=mav=m\left( \frac{dv}{dt} \right)v=\frac{P}{m}dt=vdv\] \[\Rightarrow \]\[\frac{P}{m}\times t=\frac{{{v}^{2}}}{2}\Rightarrow v={{\left( \frac{2P}{m} \right)}^{1/2}}{{t}^{1/2}}\] Now, \[s=\int_{{}}^{{}}{vdt}={{\int_{{}}^{{}}{\left( \frac{2P}{m} \right)}}^{1/2}}{{t}^{1/2}}dt\] \[\therefore \]    \[s={{\left( \frac{2P}{m} \right)}^{1/2}}{{t}^{1/2}}dt\] Hence, the correction option is [c].


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