Question

What is the Earth's gravitational force on you when you are standing on the Earth and when you are riding in the Space Shuttle 380 km above the Earth's surface? Answer as a fraction of the surface gravity of Earth. (The Earth's radius is 6400 km.)

Answer 1

F = G Mearth Moject / r^2

F1 = G Mearth m/6400^2
F2 = G Mearth m/6780^2
so

F2/F1 = (6400/6780)^2 = 0.891

Answer 2

Calculate the acceleration due to gravity when a spaceship is at a distance equal to twice the earth radius from the centre of the earth