Center of Gravity (bottles)
Improbably, the water bottle balances perfectly when placed in the wood holder. This is because the base of the piece of wood is directly below the center of gravity of the combination.
Materials
- a long-necked water bottle
- a wooden slat
Construction Instructions
Fill the bottle with water and tape the cap shut.
Cut a hole in the slat of wood as shown, and mitre the base of the slat appropriately.