# Homework Help: Calculate the weight of the satellite on the surface of the Earth

1. Nov 10, 2005

### SoccaCrazy24

A communications satellite with a mass of 340 kg is in a circular orbit about the Earth. The radius of the orbit is 27800 km as measured from the center of the Earth.
(a) Calculate the weight of the satellite on the surface of the Earth.
(b) Calculate the gravitational force exerted on the satellite by the Earth when it is in orbit.

Well here are some information needed for the problem...
Mass of earth = 5.97x10^24 kg
Radius of earth = 6,356,908.8 m

But for b.. I used the equation Fg= G(m1*m2)/r^2
so... Fg = (6.67x10^-11 * 340 * 5.97^24)/(27800000-6356908.8)^2 = 294.4 N is this right? because it asks for it in kN which is .2944 kN did i do something wrong somewhere because somehow that isnt right...

2. Nov 10, 2005

### Diane_

The distance in Newton's Law of Gravitation is from the center of mass of the two objects involved. In this case, it'll be essentially from the center of the Earth, not from the surface.

3. Nov 10, 2005

### SoccaCrazy24

thanks diane...