Question

If force on a block is $F=8/x^2$ where $x$ is displacement ,then find total work done in moving block from from $x=2m$ to $x=6m$

Answer 1

Given that,

Force on the block , $F=\frac{8}{x^2}$

Work done in moving the block from $x=2m$ to $x=6m$, $W={\int }_2^{6}F\cdot dx={\int }_2^6\left(\frac{8}{x^2}\right)dx=[-\frac{8}{x}{]}_2^6=(-4+\frac{8}{6})=\frac{-8}{3}J$