- a ruler with a rubber band around it
- a hammer
- a table
- Hold the ruler with the rubber band dangling near one end. Slide the hammer handle through the rubber band. The metal head should hang down, while the handle touches the ruler.
- Set the tip of the ruler on the edge of a table. The head of the hammer should hang under the table. It looks like it should fall, but when you let go... it stays in place!
Where do you think the center of gravity of the hammer is?