I was able to run it in jar sir, i just really need ur help of providing the source code like the one you provided for the 2D Collision at this url http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=4 for this collision simulation, i was able to compile and run the one you gave for the 2D Collision, because the main function didn't have to extend any other package, if possible could you send it to this email, tera_xollaravo@yahoo.com, appreciate it much.