Hi guys, I'm currently doing a little project an I need to calculate the speed of a satellite around the sun! I'm currently trying with the Earth, but i have some problem. When i'm using this formula : (2*Pi*a*Sqrt(1-e2))/T(1±e) I get an answer in km/s which seams pretty good. (29,75 km/s) But when i'm using this one : Sqrt(G*M*(2/r)-(1/a)) i'm getting 1,32*1017 I don't really know how I can transform that answer into something in km/s If i'm not clear enough, feel free to ask me questions! Thanks!