text: The Force acting on a mass of m kg  is\n\n F = G M m / R^2 \nwhere  G =6.673x10^ (-11) Nm^2/kg^2; M, the mass of earth =5.978x10^24kg and R, the distance of the mass from earth \n=  ( 12800 +6400)x10^3m.\n\nThe acceleration on the mass is \n\nF/m = G M / R^2\n\nThis acceleration is the centripetal acceleration for the object \n= V V /R.\n\nEquating the two and canceling one R from both sides,\n\nV V = GM / R.\n\n ---- = (6.673x10^ (-11) x 5.978x10^24) / R\n\n---- = 3.99 x 10^ 14 / R\n\n---- = 3.99 x 10^14 / 19.2 ^ 6 \n\nV = 4558 m/s