If a person weighs 882 n on the surface of the earth, at what altitude above the earth’s surface must they be for their weight to drop to 800 n

To calculate weight we use formula:


When we have two bodies we use general gravity formula:

Where:
G = gravity constant = 
Mp = mass of person = 882 / 9.81= 89.9kg
ME = mass of Earth = 
r = distance between Earth and person

From these two equations we find that left sides are equal so the right sides must be equal too.


We solve this for r:

r=6371116m = 6371.116km

This is distance from center of Earth. Radius of Earth is 6370km and height above surface is 6371.116 - 6370 = 1.116km or 1116m.