What is its free$-$fall acceleration due to the Earth's gravitational field, in$($ m$)/($s$)2?[$Hint: You do not need to know the value of G$.$ Rather, compare g$($r$)$ to g$($RE$)=9\mathrm{.}80($ m$)/($s$)2,$ the gravitational field at the Earth's surface, knowing how the field varies with radial distance r from the center of the Earth.$]$