Let's see
We need distance between them?
[tex]\\ \rm\Rrightarrow F=\dfrac{GMm}{r^2}[/tex]
[tex]\\ \rm\Rrightarrow r^2=\dfrac{GMm}{F}[/tex]
[tex]\\ \rm\Rrightarrow r^2=\dfrac{6.673\times 10^{-11}\times 8.1\times 10^2\times 4.5\times 10^8kg}{1.9\times 10^{-3}}[/tex]
[tex]\\ \rm\Rrightarrow r^2=128.02\times 10^{2}[/tex]
[tex]\\ \rm\Rrightarrow r^2=12802[/tex]
[tex]\\ \rm\Rrightarrow r=\sqrt{12802}[/tex]
[tex]\\ \rm\Rrightarrow r=113.14m[/tex]
