A man has a mass of 60 kg on the Earth's surface.

Question

How far above the surface of the Earth would he have to go to "lose" 10 % of his body weight?

Express your answer using two significant figures.

Answer 1

I will set up the solution, but YOU do the calculations.

h = required height above the surface of the Earth to weigh 10% less than on the surface

R = radius of Earth

G = universal constant of gravitation

m = mass of man = 60 kg

M = mass of earth

You need to solve for h in the equation below:

GMm / (R + h)^2 = 0.90 GMm / R^2

Note the solution does not depend on G, M, or m. Solve for h in

1 / (R + h)^2 = 0.90 / R^2

(R + h)^2 = R^2 / 0.90

You can finish from here.