Percepatan gravitasi rata rata di permukaan bumi yaitu g. Untuk tempat pada ketinggian 2R dengan R adalah jari jari bumi, percepatan gravitasi nya sebesar... a.

Dik : g1 = g, r1 = R, r2 = 2R
Dit : g2 = ...?
Jwb:
$
\begin{array}{l}
{{Dik}{\mathrm{:}}{m}_{1}\mathrm{{=}}{4}{kg}{\mathrm{;}}{m}_{2}\mathrm{{=}}{8}{kg}{\mathrm{;}}{r}\mathrm{{=}}{2}{m}}\\
{{Dit}{\mathrm{:}}{F}\mathrm{{=}}{\mathrm{...?}}}\\
{{Jwb}{\mathrm{:}}{F}\mathrm{{=}}{G}\frac{{m}_{1}{m}_{2}}{{r}^{2}}}\\
{\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\mathrm{{=}}{6}{\mathrm{.}}{6}{7}\mathrm{\times}{\mathrm{10}}^{\mathrm{{-}}{\mathrm{11}}}\mathrm{\times}\frac{\rlap{/}{4}\mathrm{\times}{8}}{}}\\
{\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\mathrm{{=}}{6}{\mathrm{.}}{6}{7}\mathrm{\times}{8}\mathrm{\times}{\mathrm{10}}^{\mathrm{{-}}{\mathrm{11}}}}\\
{\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\mathrm{{=}}{5}{3}{\mathrm{.}}{3}{6}\mathrm{\times}{\mathrm{10}}^{\mathrm{{-}}{\mathrm{11}}}}\\
{\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\mathrm{{=}}{5}{\mathrm{.}}{3}{4}\mathrm{\times}{\mathrm{10}}^{\mathrm{{-}}{\mathrm{10}}}{N}{\mathrm{.}}}
\end{array}