//Orbital velocity (sqrt(G*M/r))
var G = 6.67e-11; //gravitation constant (Nm^2/kg^2)
var M = 5.972e24; //Mass of earth (kg)
var rEarth = 6.371e6; //distance from center of earth to surface (m)
var h = .781e6;//height of satellite above the surface (m)
var r = rEarth + h;

var V=sqrt(G*M/r);  // Velocity - (test should equal 7,462 meters/second)
var T=2*math.pi*r/V // Period - (test should equal 6019 seconds)

canvas.append("text")
    .text(V)
    .attr(29, 20);