Difficulty: 2 out of a possible 10 very easy!
- A block of wood with one nail already securely in place
- 12 identical nails with heads (the nails should be 10 penny size or larger)
1. Putting one nail into the wooden block
2. Place the wood block flat on a desk or table.
3. None of the eleven nails should touch the wood block, the desk or table, or anything else that might help hold them up. No additional equipment other than the wood block and the nails may be used.
4. Put on nail down horizontally, and line four facing toward you on one side and four facing away from you on the other.
5. Put the reminder nail on top
6. Slowly move the now touching nails on top of the one nail which is secured in the wooden block.
If the demonstration went right, 10 nails would be balanced on one. The nails seem as though they are defying gravity but in reality their center of gravity is equal to the other side.Gravity pulls an object down as if all of its weight were concentrated at one point called the "center of gravity." Objects fall over when their center of gravity is not supported. For symmetrical objects like a ball or a meter stick, the center of gravity is exactly in the middle of the object. For objects that are not symmetrical, like a baseball bat, the center of gravity is closer to the heavier end. The stability of the nails depends on their center of gravity being right at or directly below the point where they rest on the bottom nail. Add too many nails to the left or right and they become unstable and fall off. Since the nails have equal weight ratio on all sides the nails do not fall. All in all, due to center of gravity and equal forces acting on the nails causes the nails to appear as though they are defying gravity. (Amazing song my I add)