1. The problem statement, all variables and given/known data (a) Determine the energy, in kW·h, necessary to place a 1.0-kg object in low-Earth orbit. In low-Earth orbit, the height of the object above the surface of Earth is much smaller than Earth's radius. Take the orbital height to be 300 km. G = 6.67*10^-11 Me = 5.97*10^24 Re = 6.37*10^6 m = 1 Ro = 300000 2. Relevant equations E = K + U U = (G*Me*m)/r K = .5U 3. The attempt at a solution What I've done is plugged in all known variables into E = K + U where r = Re + Ro. I get a final answer of 29850000J. Converting to kWh using 1 kWh = 3600000J, I get 8.29kWh. According to the book, this is incorrect. My number should be 8.7kWh. I have plugged this number into my online homework site, and it is incorrect. Can someone tell me what I'm not doing correctly?