We warmed up with some intuition building games. We asked kids to stand at the very end of the board and adjust the board's position until balance was achieved. We marked the fulcrum point for each pair and saw how different they where.
Then it was right back to building. We had made it so far last time and this time we where determined to finish our 16 Ft teeter-totter.
From there we put panels on the top, screwed it down and were excited for our first trial of the larger than life scale.
The moment we got on our 16ft lever arm, it bent. Both sides weekly flopped the ground. The structure wasn't strong enough. Disappointment floated in the air for just a moment until Sean came up with he idea to clamp some 4x4's to the center.
It worked! The beam was sturdy and we could start balancing. Immediately the kids started figuring out how to balance themselves, and began measuring how far from the center they were and how much they weighed. Then, a game began. Josh said that all he need to know was the weight of one person, and the distance of each person from the center (when everything was in balance) and he could accurately predict the other persons weight. Super powers? Magic? No, science! We spent the rest of the day guessing weights, often within 2 lb. (2.5% error).
Next week we will unveil the mysterious equation that wielded so much predictive power.