Wrap the rubber band around the ball.
Attach the string to the rubber band.
Tie the other end of the string to the handle or piece of pipe. The ball should clear the floor by about 3 to 5 inches and be able to swing freely. Ask your child to identify the pivot point.
Build a tower of blocks. Measure the height of the tower so your child can build to the same height as they test varying pivot points.
Rest the handle or pipe on the back of the two chairs and have two helpers hold each end steady.
Have one student hold the pendulum at the ready to let it go and knock the blocks. But, before they let go, have another person measure the height of the ball. Record that height on a piece of paper.
How many blocks fell over? How far did they travel when knocked over? Now hold the ball farther back. What happened as the wrecking ball was pulled back more and more?