- #1

MiniOreo1998

- 18

- 0

## Homework Statement

The Earth has a mass of 5.98 x 10

^{24}kg and the moon has a mass of 7.35 x 10

^{24}kg. The distance from the centre of the Moon to the centre of the Earth is 3.84 x 10

^{8}m. A rocket with a total mass of 1200 kg is 3.0 x 10

^{8}m from the centre of the Earth and directly in between the Earth and Moon.

Find the net gravitational force on the rocket from the Earth and Moon.

If anyone spots any mistakes (or clearer ways that I could have written things out) let me know!

Thanks in advance, coming to this site and reading through some of the threads has started to boost my confidence.

## Homework Equations

Fg = m1 m2 / r

^{2}

## The Attempt at a Solution

Fg = m1 m2 / r

^{2}

Earth & Rocket: Fg (6.67 x 10

^{-11}) (5.98 x 10

^{24}) (1200) / (3.0 x 10

^{8})

^{2}

Fgnet

_{rocket}= 5.318 N

Moon & Rocket: Fg (6.67 x 10

^{-11}) (1200) (7.35 x 10

^{22}) / (8.4 x 10

^{7})

^{2}

Fgnet

_{rocket}= -0.8337 N

Adding together to get:

Fgnet

_{Rocket, Earth}5.318 N + Fgnet

_{Rocket, Moon}(0.8337 N) = 4.48

Fgnet

_{rocket}= 4.48 N