You can download source code by yourself, you have to look up the applet, you gonna found to options: [b]send to my email account[/b] [b]download file(1364/1028)[/b]
Choose download file(1364/1028) and click at [b]Get Files For Offline Use Button[/b] and you will be already to download the source at your PC as winzip, unzip and enjoy  the physic applet.