# Gravity problem< normal force

#### bobsagget

Q:Astronomers have found a new planet in our solar system and have decided to call it planet angeles. Planet angelees has only one moon. Planet Angeles mass is 90 times more massive than its moon. The center to center distance between angele's and its moon is 7.90 x 108 m. How far from the center of planet Angeles would a space shuttle have to be so it would experience no net force?

So i tried to get it started, and i knew i need to try and find the gravity of the planet and its moon, and then the distance that the normal force would have to equal gravity so there was no net force, i just dont know where to start, and need help on trying to get to the answer, Thanks! :shy:

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#### tiny-tim

Homework Helper
Hi bobsagget!
… i knew i need to try and find the gravity of the planet and its moon, and then the distance that the normal force would have to equal gravity so there was no net force …
Normal force requires there to be a surface.

This shuttle is cruising in space, not touching anything …

just calculate where the two gravitational forces will be equal and opposite.

#### bobsagget

ooo alright, so basically u need to get the gravity of the planet and the moon equal to each other to find where the net force or gravity is equal to 0, so the shuttle doesn't move.

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