Q.

A particle of mass m moves on a straight line with its velocity increasing with distance according to the equation v=αx, where α is a constant. The total work done by all the forces applied on the particle during its displacement from x=0 to x=d, will be                    [2024]

1 m2α2d  
2 md2α2  
3 mα2d2  
4 2mα2d  

Ans.

(3)   

         v=αx

          at x=0:v=0 and at x=d;v=αd

          W.D. =Kf-Ki

          W.D.=12m(αd)2-12m(0)2

           W.D =mα2d2