A conservative force F is in the $+$x direction and has magnitude F$($x$)=$ a$/($x $+$ x$0)($ x$+$x$0)$ where a$=0\mathrm{.}15$ N$.$m$.$m and x$0=0\mathrm{.}2$ m$.$ What is the potential energy function U $($x$)$ for this force? Let u$($x$)$ is going to $0$ as x is going to infinity? And An object with mass m $=0\mathrm{.}500$ kg is released from rest at x $=0$ and moves in the $+$x$-$direction. If F is the only force acting

on the object, what is the object's speed when it reaches x $=0\mathrm{.}400$ m$?$