Enter the total mass of an object or satellite, and the radius at which is is orbiting to calculate the velocity of that object. This is only valid for an object orbiting Earth in a mostly circular orbit.
Orbital Speed Formula
The formula for orbital speed is the following:
Velocity (v) = Square root (G*m/r)
Where G is a gravitational constant, m is the mass of earth (or other larger body) and radius is the distance at which the smaller mass object is orbiting.
For Earth, G*m = 3.986004418*10^14 (m^3/s^2)
If you didn’t recognize it yet, you can see that the velocity of an object orbiting Earth is only dependent on the radius or distance it is orbiting. This is because the mass of the object orbiting the Earth is so small in comparison that it’s negligible.
Through some manipulation of the equations, we can actually determine the force or torque required to keep that object at that velocity due to angular acceleration.
The following equation can be use:
F = G*M*m/r^2
Where G is the gravitational constant, M is the mass of Earth, m is the mass of the orbiting object, and r is the distance of orbit. In this case the ass of the smaller object is also negligible.
How to calculate orbital speed
We will now take a look at an example of how to calculate orbital speed of a satellite in orbit around earth.
For more science related calculators, click here.