posted by Carolyn Bautista .
A communcations satellite of mass 200kg is in circular orbit of radis 4x10^4 km measured from the center of the earth. What is the gravitational force on the satellite and what fraction is this of its weight on the surface of the earth?
On the surface of the earth, the weight weight would be
W = M*g = 200*9.8 = 1960 Newtons
The Earth's radius is 6370 km. Your orbit radius is 40,000 km. The weight is proportional to 1/R^2, so at 40,000 km the weight is
1960*(6370/40,000)^2 = 49.7 Newtons