well over Mach 20 (7 km/s) well over Mach 20 (7 km/s) Variation of $g$ with altitude Earth orbits Hyperphysics questa pagine web well over Mach 20 (7 km/s) Variation of $g$ with altitude Variation of $g$ with altitude well over Mach 20 (7 km/s) questa pagine web Calcolo dei parametri dell'orbita Variation of $g$ with altitude Variation of $g$ with altitude