The Ejs Free Fall Polar model displays the dynamics in polar coordinates of a ball launched near the surface of Earth onto a platform.  The initial conditions for the ball are a negative initial velocity in the radial direction and a positive initial velocity in the theta direction (or positive initial velocities in both the x and y directions).  The coefficient of restitution for the ball's collision with the platform is less than one.  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 Free Fall Polar 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_newton_FreeFallPolar.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).