posted by alex on .
A 80 kg man weighs 784 N on the Earth's surface. How far above the surface of the Earth would he have to go to "lose" 15% of his body weight?
Let Re be the earth's radius and h be the required altitude. Since g is inversely proportional to radius squared,
[Re/(Re + h)]^2 = 0.85
Look up Re and solve for h