Calculate the force of the Earths gravity on a spacecraft 12,800 km (2 earth radii) above the Earths surface if its mass is 1350 kg?

Answer 1

F = GMm/r^2 = 6.673*10^-11 * 5.973*10^24 * 1350 / (6378*3000)^2 = 1464N

makes sense - roughly 3 times as far, so 1/9 the force at the surface