What is the gravitational force between mars and Phobos

Answer:
[tex]F=5.16\times 10^{15}\ N[/tex]
Explanation:
We have,
Mass of Mars is, [tex]m_M=6.42\times 10^{23}\ kg[/tex]
Mass of its moon Phobos, [tex]m_P=1.06\times 10^{16}\ kg[/tex]
Distance between Mars and Phobos, d = 9378 km
It is required to find the gravitational force between Mars and Phobos. The force between two masses is given by
[tex]F=G\dfrac{m_Mm_P}{d^2}[/tex]
Plugging all values, we get :
[tex]F=6.67\times 10^{-11}\times \dfrac{6.42\times 10^{23}\times 1.06\times 10^{16}}{(9378\times 10^3)^2}\\\\F=5.16\times 10^{15}\ N[/tex]
So, the gravitational force is [tex]5.16\times 10^{15}\ N[/tex].