Just thought I could give some of my findings and see what other people have found out.

First, objects appear to have set mass, regardless of their size or material. Putting a large cube and a small cube on a balance at equal distance they balanced, and putting a wooden cube and a stone cube on the balance at equal distance they balanced. This effect can also be seen through catapults-a small 'ammo' cube will go to the same height as the larger 'launching' cube was dropped from.

Second, air resistance seems to be non-existent. I'm sure you will have noticed that if you knock against the ring chains they carry on swinging for at least a long time, if not forever. I have also dropped a flat wooden block at the same time and height as a wooden cube and they hit the ground at the same time.

Third, just as each object has a set mass, two objects will have twice that mass, with my first point applying. Putting two wooden cubes half the distance from the pivot from one wooden cube makes them balance, while putting them at the same distance away from the pivot makes the balance tip towards the two cubes.

Fourthly, the law of moments appears to work just as it does in real life. A wooden cube further from the pivot tips the balances against an identical cube closer to the pivot.

Experiments I am planning for future are testing whether gravity creates acceleration, or simply makes an object fall at a set speed and numerical data must be found for whichever of these holds true (eg what the set speed is). Personally I think it will be a set speed, but we need to test this.

Any findings by anyone else?