24 October 2011

added a magnify ability to draw students attention to the lines based on codes from http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2268.0 by Fu-Kwun Hwang
randomize the size of the black object each time to simulation is reset based on a request on physics front http://www.thephysicsfront.org/items/detail.cfm?ID=9422

enjoy!