If a person has a weight of 145 lb at sea level, by how much is their weight reduced when flying on an airplane at an altitude of 10700 m?

Question

If a person has a weight of 145 lb at sea level, by how much is their weight reduced when flying on an airplane at an altitude of 10700 m?

Answer 1

Earth radius = 6371 km

airplane altitude = 10.7 km

Weight at altitude =
145 lb*(6371/6381.7)^2
= 144.51 lb

The reduction is 0.49 lb

Note: Yoy do not have to convert the altitudes to feet or miles, because we only needed to use a ratio of distances from the center of the earth. Ratios are dimensionless.