Question

A man weighs 300N on the surface of the earth. If he were taken to the moon his weight would be 50N. Calculate the mass of this man on Moon if g=10m/s^2

Answer 1

g` = g(r/(r+h))^2 Where:



g` is gravity at some altitude.



g is gravity near earth’s surface.



r is earth’s mean radius.




h is the altitude.

Now for you to feel half of your weight, g` should be half of g.




This means h should be ~2639 KM (Assuming earth’s mean radius = 6371 KM).

So if you reach at a height of about 2700 KM above the sea level, you body will weigh around 30 N.