posted by dave .
How do I calculate the orbital velocity of a satellite that is 400 miles above the earth?
Set the centripetal acceleration V^2/(R+h) equal to the gravitational acceleration, g * [R/(R+h)]^2
Then solve for V
R is the earth's radius and h is the 400 mile height. g is the acceleration of gravity at the earth's surface. It decreases with distance^2 from the center of the Earth. I suggest using metric units.