The acceleration due to gravity at height \( h \) above the earth if \( h << R \) (Radius of earth) is given by:
\( g' = g \left( 1 - \dfrac{2h^2}{R^2} \right) \)
\( g' = g \left( 1 - \dfrac{2h}{R} \right) \)
\( g' = g \left( 1 - \dfrac{h}{2R} \right) \)
\( g' = g \left( 1 - \dfrac{h^2}{2R^2} \right) \)