Static of Rigid Bodies
Balance Nine Nails on One
Ask students if they can balance 10 nails on the head of the 1 nail in the block. Then show them how. Lay 1 nail down, then place 4 on each side perpendicular to the 1 and their head up next to the nail. Then place the last nail running in the opposite direction to the original nail on top of the 8 nail heads to hold them down. Pick up the "contraption" by both ends pinching the ends to hold the 8 nail heads between the long nails. Place them symmetrically on the head of the blocked nail. They should balance steadily.