Centripetal Acceleration of object orbiting earth

[Fusilli_Jerry89]

Homework Statement

An object orbits the Earth at a constant speed in a circle of radius 6.38x10^6m, very close to but not touching the Earth's surface. What is its centripetal acceleraion?

Homework Equations

The Attempt at a Solution

Quick question, when would GM/r^2 equal to the centripetal acceleration, and when wouldn't it? I thought it always did but some calculations don't have the same numbers if you do it both ways. For this question would it be?

 

[Dick]

Well, force is GMm/r^2 (Newton et al) and acceleration is force/m (Newton et al). So acceleration=GM/r^2. If you have evidence otherwise, cough it up.