• question_answer A particle is displaced from $x=-6\text{ }m$ to $x=+6\text{ }m$. A force F acting on the particle during its motion in shown in figure. Graph between work done by this force (W) and displacement (x) should be      A) B) C) D)

[a] W = Area under F-X graph.   From $x=-6\text{ }m$to$x=0$, force is in negative x-direction and displacement is in positive x-direction. Therefore, work done will be negative and since force is constant, W-x graph will be a straight line. From $x=0$to $x=+3$m, force is negative and displacement is positive, hence, work done will be negative and W-x graph will be a parabola. From $x=+3\,m$to$x=+6\,m$, force and displacement both are positive, therefore, work done is also positive and W-x graph will be a parabola.