A satellite is orbiting close to the surface of the earth, then its speed is
$\sqrt{2gR}$
Rg
$\sqrt{Rg}$
$\sqrt{\dfrac{Rg}{2}}$
Next Question
If the change in the value of g at the height h above the surface of the earth is the same as at a depth x below it, then (both x and h being much smaller than the radius of the earth)