(a) What is the potential energy: PE = -G * M * m/r
Where: M is the mass of the earth which is 5.98 * 10^24 kg.
m is the mass of the satellite.
r is the space from the center of the earth to the satellite
To conclude this distance add the radius of the earth to the altitude. Radius of the earth is 6.38 * 10^6 meters.
r = 6.38 * 10^6 + 2.02 * 10^6 = 8.38 * 10^6
PE = 6.67 * 10^-11 * 5.98 * 10^24 * 99/8.38 * 10^6 = 4.71240095 * 10^9 J
(b) magnitude of the gravitational force exerted by the Earth
Fg = G * M * m/r^2
Fg = 6.67 * 10^-11 * 5.98 * 10^24 * 99/(8.38 * 10^6)^2 = 562.3078873 N
(c) There are no other forces that the satellite exert on the Earth. So therefore, it is 0.
