RangerDanger75 Posted July 19, 2011 Share Posted July 19, 2011 I've seen the equation around here before, but I can't seem to find it anymore. Does anyone know the formula for escape velocity? I know it's something about taking the square root of the orbital velocity and multiplying by something or another or something like that. Link to comment Share on other sites More sharing options...
UmbralRaptor Posted July 20, 2011 Share Posted July 20, 2011 sqrt(2GM/r), or ~1.4*(circular) orbital speed.(G is the gravitational constant, M is the mass of what you're orbiting/want to escape from, and r is how far away from it you currently are) Link to comment Share on other sites More sharing options...
Finrandojin Posted July 20, 2011 Share Posted July 20, 2011 or you can use this handy table that has the escape velocity and orbital velocities for heights from 35 km to 950 km spaced every 5 kmhttps://gist.github.com/1075144 Link to comment Share on other sites More sharing options...
RangerDanger75 Posted July 20, 2011 Author Share Posted July 20, 2011 sqrt(2GM/r), or ~1.4*(circular) orbital speed.(G is the gravitational constant, M is the mass of what you're orbiting/want to escape from, and r is how far away from it you currently are)What are you using for the mass of Kearth? The wiki says 5.29e22 kg but when I use that I don't get the right answers. Link to comment Share on other sites More sharing options...
cjameshuff Posted July 20, 2011 Share Posted July 20, 2011 What are you using for the mass of Kearth? The wiki says 5.29e22 kg but when I use that I don't get the right answers.That is what I used as the mass, and I first derived it from measurements of an orbit before noticing that the resulting surface acceleration was one gravity.Double checked:sqrt(2*G*5.29e22 kg/600 km) = 3430.27 m/s, just as it is in the table. Link to comment Share on other sites More sharing options...
Recommended Posts