1. How can i prove that Eg = mgh 2. What is the total energy needed to place a 2.0x10^3-kg satellite into circular Earth orbit at an altitude of 5.0x10^2 km? For number 2, the answer is apparently 6.7x10^10J. However, shouldn't Total Energy = 1/2 (Eg)? If that is the case, the answer would be 5.8x10^10J. (P.S. in the question after this, i must calculate the additional energy required to allow the object to escape Earth's orbit, and the answer is 5.8x10^10J).