Velocity to Keep Object in Orbit Above Moon - Jeffrey

[jeffreydi]

I am trying to find velocity which is needed to keep any object which is in orbit outerspace just above the surface of the moon. Help appriciated...
Jeffrey

 

[Wallace]

Try thinking about this more generally. You have an object moving in a circular path (in this case in orbit around the moon). In order to maintain this path there must be a centripetal force acting, in this case gravity. Write down the gravitational force between the object and the moon and equate it to the centripetal force, the answer should then be just a few lines of algebra away.

Good luck!

 

[jeffreydi]

interesting, a (centripetal) = v^2 over r, where r is mean radius of moon, and a (centripetal) is 1.6 m/s^2, one can solve for v.
I think I got it, thanks buddy.