Homework Help: Circular Motion Please Help

At what height above the earth's surface would a satellite have to orbit in order that it be stationary in reference to a point on the earth? What would be it's speed? How would you describe the general location of that point in relation to the earth's surface?



2. Relevant equations
v=2PIr/T, ac=v^2/r, ac=4PI^2r/T^2
Fc=M v^2/r, Fc=M 4PI^2r/T^2, Fg=G m1m2/r^2


I know that the satellite would have to be moving faster than the earth because if not the satellite could not stay stationary with that point on the earth. I have the radius and mass of the earth so I can figure out everything as far as speed, force, acceleration, and the period for the earth but because nothing is given for the satellite I do not know how I should figure out the speed of the satellite. I also know that to get the height you can use the equation (H = radius of earth - radius of satellite), but am not sure how I am supposed to get the radius of the satellite because again no inoformation is given for the satellite. I have tried combining some of the above equations but have come up empty handed. Any help would be appreciated.

 

Thanks for your help.