Orbit Approximation  by Carl Martikean   Your Assumptions |
Effect of the Central Force | Scale the Plot | Computing Dv|
Making the Plot | Prepare for Discussion | More Things to Do
This experiment is an interesting variation a centripetal force
experiment. In the centripetal force experiment, a mass, usually
a rubber stopper is rotated on a string and the period of
rotation is used to verify that there is a central force.
Perhaps a plot of the orbit either of Mercury or of Mars is
performed on Polar graph paper to examine the orbital
eccentricity. (Kepler was lucky that he studied Mars first!) For
an interesting synopsis of the historical significance of Comets
see this.  Newton used this concept of a centrally directed
force to analyze the motions of orbiting bodies. What I propose
here is to develop an approximate orbit of a comet or other
satellite. The plot can be used to verify Kepler's law of areas.
Based on your knowledge of Newton's laws of motion:  Q1. What
would you predict for the path of a ball