I understand circular motion.
I understand Keppler's laws of planetary motion that indicate that as the Cp force changes (due to varying radius of rotation) the tangential vleocity changes, such that the area swept out remains constant, i.e. a change in velocity indicates a change in force.
Visualisation of this is counterintuitive, but it helps of you imagine how to create the motion (try attached to a sealed piston of gas) If you ignore friction etc. once started the system continues without additional energy, and the linear force is seen on the piston.
If the system starts to translate through space, then the work done on one side is greater than that on the other. An effect not identical, but similar to the advancing vs retreating blade on a helicopter. Hence where the energy transfer occurs.
Good luck with the 2nd degree.