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## Homework Statement

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.

## Homework Equations

Fg = Gm1m2 / r^2

## 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.