The Ejs Non-Newtonian Orbit model displays the dynamics of a mass orbiting a much larger mass subject to non-Newtonian gravity.  The simulation displays the motion of the smaller mass and the effective potential energy diagram.  The initial energy of the system can be changed via textbox and the initial conditions can also be changed by dragging the mass or dragging the pink circle in the effect potential energy diagram.  You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item.  

Ejs Non-Newtonian Orbit model was created using the Easy Java Simulations (Ejs) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking the ejs_ehu_central_forces_precession.jar file will run the program if Java is installed.  Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models.  Additional Ejs models for Newtonian mechanics are available.  They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Please note that this resource requires at least version 1.5 of Java (JRE).