Does a satellite with a large or small orbital radius have the greater velocity?

The larger the orbit, the slower the velocity is. It is like spinning a weight on a string. The string is gravity. From the formula below, you can see that we divide by the radius of the orbit. As the radius increases, the velocity of the satellite decreases.

Orbital velocity (also called circular velocity) is the speed of a satellite in orbit around a planet. The formula for circular velocity is given in the text as:

Vc= square root of (GM/r))

where r is the distance from the satellite to the center of the planet, M is the mass of the planet and G is a fundamental constant of nature, given as .

The two most important things to remember are: (1) be sure to work with distances in meters or the units won't work out, and (2) add the radius of the planet to the distance of the satellite above the surface.
 
Back
Top