Charles, I'm not confusing anything. Orbital 'velocity' describes a curve, not the tangential velocity. Newton derived the orbital velocity from the tangential velocity, so they can't be equivalent. He took the tangential velocity as his given in order to calculate the orbital 'velocity'. You can't take your given, derive a new 'velocity' and then claim that it is equivalent to your given. What's the point of the derivation then? Orbital 'velocity' is measured in distance/time as with any velocity. But velocity is always one-dimensional. The path of the orbit is not one-dimensionsal; units have been dropped. Where did they go? The mechanics of orbital velocity REQUIRE that the units be in at least m^2/s^3; those are the units you get when you combine a tangential velocity (m/s) with a centripetal acceleration (m/s^2).

 

tharkun