This is a test, and I believe it only works in Firefox correctly after intalling this program: http://www.dessci.com/en/products/mathplayer/
A satellite is orbiting around the earth at a height of 20,000 km. What is its orbital speed?
[mathml]R_(earth) = 6.378*10^8 cm[/mathml]
[mathml]M_(earth) = 5.974*10^27 g[/mathml]
[mathml]G_(const) = 6.67259*10^(-8) cm^3/(g*s^2)[/mathml]
[mathml]v_(orbit) = G_(const) * M_(earth) / (R_(earth) + R_(satellite)) = 3886 m/s[/mathml]