What is the velocity of a satellite in a circular orbit?

A satellite in a circular orbit travels at a particular velocity. A satellite in a circular orbit travels at a velocity such that its kinetic energy is equal to its weight. For a satellite in a circular orbit, we can write the following equation:

W = KE

We can also write this equation:

W = RW – KE


Combining these two equations,


KE = RW – KE


2KE = RW


mv ² = GMm / r


v ² = GM / r

What is the weight of a one kilogram body on the surface of the Earth?

The formula for rest weight is:


RW = GMm / r


The value of GM for a planet can be calculated from the formula for the velocity of a satellite in a circular orbit around the planet. The value of GM for the Earth is 399 trillion meters cubed per seconds squared.  The mean radius of the Earth is 6,371,000 meters. The weight of a one kilogram body at rest on the surface of the Earth is 63 million joules.