1. The problem statement, all variables and given/known data The earth has a mass of 5.98x10^24 kg and the moon has a mass of 7.35x10^22 kg. The distance from the centre of the moon to the centre of the earth is 3.84x10^8 m. A rocket with a total mass of 1200 kg is 3.0x10^8 m from the centre of the earth and directly in between earth and the moon. Find the net gravitional force on the rocket from the earth and moon. 2. Relevant equations Fg = Gm1m2 / r^2 3. The attempt at a solution I think the above is the equation I'm suppose to be using. I have hard time grasping this concept :S. And this is what I did Fg on the rocket to the earth: Fg = (6.67x10^-11)(5.98x10^24)(1200) / (3.0x10^8)^2 Fg = 5.3182 N Fg on the rocket to the moon: Fg = (6.67x10^-11)(7.35x10^22)(1200) / (3.0x10^8 + 3.84x10^8)^2 Fg = (6.67x10^-11)(7.35x10^22)(1200) / (6.84 x10^9)^2 Fg = 1.2574 x 10^-4 N Fgnet = 5.3182 N + 1.2574 x 10^-4 N Fgnet = 5.3183 N I'm not sure if this is correct or not :S. From my understanding it seems to be. Please help.