A particle of mass 500 gm is moving in a straight line with velocity $v=b x^{5 / 2}$. The work done by the net force during its displacement from $x=0$ to $x=4 \mathrm{~m}$ is : (Take $\left.\mathrm{b}=0.25 \mathrm{~m}^{-3 / 2} \mathrm{~s}^{-1}\right)$.
