

Mass of the Earth, M = 6.0 × 1024 kg
Radius of the Earth, R = 6400 km = 6.4 × 106 m
Height of a geostationary satellite from the surface of the Earth,
h = 36000 km = 3.6 × 107 m
Gravitational potential energy due to Earth’s gravity at height h,
= -GM / (R + h)
= - 6.67 × 10-11 × 6 × 1024 / (3.6 × 107 + 0.64 × 107)
= -9.4 × 106 J/kg.
