FYI: Real gravity will accelerate an object at 32 feet per second per second. This means that every second an object will falll another 32 feet further than the last time. Over short distances this is almost impossible to see. I don't know if GS-PE or Newton's PE includes this force, but if not I am sure you are able to implement this....
i.e increase the accelerated downward force by 32' x 12" x 2.54mm = 975.36mm per second...or more accurately over that entire second.....
As for working that out according to the gravity formula....(–9.81 * 100 / 2.54)....no idea....lol
hope thats not completely useless...