Downloads:

Flash 6 plug-in

HardDynamSim.fla
(Source file)

HardDynamSim.exe
(Windows standalone executable)

HardDynamSim
(Mac standalone application)

Credits:

William Fawcett

Notes:

Try changing from a positive to negative gravity value (or vice versa) to see the ball stick to the opposite end. You can also change the values whilst the ball is moving. A bowling ball on the moon might have the values 0.94 / 0.7 / -0.3!