Q.

A body is moving unidirectionally under the influence of a constant power source. Its displacement in time t is proportional to                    [2024]

1 t  
2 t2  
3 t2/3  
4 t3/2  

Ans.

(4)     

           dWdt=PdW=Pdt

            F·ds=Pdt

           mdvdsdt=Pdt

          0vvdv=Pm0tdtv22=Ptm

           Hence,  vtdsdt=Ct, C is a constant

           0sds=C0tt1/2dt

          s=C23t3/2st3/2

           displacement of proportional to (t)3/2