1. The problem statement, all variables and given/known data If the gravitational accleration at the Earths surface is 9.81 m/s^2 what is its value at a height equal to the diameter of the earth from its surface? 2. The attempt at a solution I have heard that it becomes 1/4th the value as the center of mass is moving away form each other. But I really can't understand the idea. Why is it 1/4?