At what altitude above Earth would your weight be one-half your weight on the surface? Use Earth's radius, rɛ, as the unit. AA In a hydrogen atom, a proton and an electron are5.3 × 10-1" m apart. Calculate the magnitude of the gravitational attraction between the proton and the electron. The mass of a proton is 1.67 × 10 " kg, and the mass of an electron is 9.11 × 10 " kg. A-31 Two objects are a distance r apart. The distance r increases by a factor of 4. u (a) Does the gravitational force between the objects increase or decrease? Explain your answer. b) By what factor does the gravitational force between the objects change?