[tex]9.47 \times 10^{-6}\; \text{N}[/tex].
Constant of universal gravitation:
[tex]G = 6.67 \times 10^{-11} \;\text{m}^{3} \cdot \text{kg}^{-1} \cdot \text{s}^{-2}[/tex].
Apply Newton's law of universal gravitation:
[tex]F = \dfrac{G \cdot m_1 \cdot m_2}{r^{2}} =\dfrac{6.67 \times 10^{-11}\times 3600 \times 2850}{8.5^{2}} = 9.47 \times 10^{-6} \;\text{N}[/tex].