Using 2 push pins and string , the different orbitals formed when the foci are close together or far apart was sketched. A close orbit was circular while a more distant orbit was elliptical. Reviewing the definitions for kinetic energy and potential energy, the relationship between PE and KE at the apogee and perigee as well as mid points between was discussed and concluded that the PE was equal at all points and that the sum of the PE and KE was a constant. This was then compared to an elliptical orbit sketched, with the differences in energy noted at the same four points as on a circle. The change in both KE and PE was explained as well as the effect gravity has on the change in KE as the satellite orbits.