HELP! I'm trying to write a computer program (C) to plot the trajectory of the rocket as it flies from Earth to Moon. In the information sheet it says:(adsbygoogle = window.adsbygoogle || []).push({});

ax = -GMe*(1/rr^2)*(xr/|rr|) - GMm*(1/[rr-rm]^2)*([xr - xm]/[|rr - rm|])

Where:

ax = acceleration in x-direction (we're working in xy coords)

rr = a vector from the Earth to the Rocket

rm = a vectore from the Earth to the Rocket

xr = Rocket's x coordinate

xm = Moon's x coordinate

Me = Earth's Mass

Mm = Moon's Mass

Now, in order to input this acceleration in the x direction into my program I have to resolve the vector's into their x-direction BUT also be aware that their y co-ords will have an effect on the gravitational force felt in the x direction.

Could some-one explain to me what I actually have to compute then? Also, when it says "rr^2" does this mean the modulus squared?!

Please help, I'm really stuck!!! Thanks

Chloé

xxx

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Acceleration on Rocket

**Physics Forums | Science Articles, Homework Help, Discussion**