Calculate the acceleration of two different satellites that orbit Earth. one is located at 2.0Earth radii and the other located 4.0Earth radii.
Acceleration equals gravitational force divided by mass.
a = GM/R^2
G is the universal constant of gravity and M is the mass of the earth. Note that GM/R'^2 = g, the acceleration of gravity at the surface of the earth, where R = R'.
That means a = g/4 at R = 2 R' and
a = g/16 at R = 4 R'