posted by Max on .
How far above the surface of the Earth does an object have to be in order for it to have the same weight as it would have on the surface of the Moon? (Ignore any effects from the Earth's gravity for the object on the Moon's surface or from the Moon's gravity for the object above the Earth.) I think it is 9300km but im not sure I forgot the equation
Since g at the moon's surface is 1/6 of that on Earth, to get the same value in earth orbit, you would have to be sqrt6 = 2.45 times farther from the center than you are at the Earth's surface. Since the Earth's radius is 6400 km, the new distance from center would be 15,700 and the distance above the earth's surface would be 9300 km.
I agree with your answer. I have only kept two significant figure accuracy in the above calculations.