HI, I have another question related to this which I can't solve
Calculate the gravitational potential at a point 6.800×10^8m from the centre of the planet in question F5.16 on the same side of the planet as its moon. You should take the Universal gravitational constant to be 𝐺=6.674×10^−11Nm^2kg^−2. [Note: more significant figures are used in this question than appear in earlier printings of the book.]
F5.16 A 2.400×10^22 kg moon orbits a 7.200×10^24 planet with an orbital radius of 2.500×10^8m. Calculate the gravitational potential at the point half way between the centres of the planet and its moon. You should take the Universal gravitational constant to be 𝐺=6.674×10^−11Nm^2kg^−2. [Note: more significant figures are used in this question than appear in earlier printings of the book.]
=-3.857x10^6 J/kg