STRONG BRIDGES WITH MR.G!
Today we had our first visit from Mr. G and it did not disappoint. We learned about what shapes makes a strong bridge and we got to work together with our classmates to figure it out.
Problem: Do different shapes make bridges stronger?
Procedure: Place two cups six inches apart. Get a piece of poster board and place it across the top of the two cups. Then place one eraser at a time on the middle of the poster board until it falls down. Try this again with the poster board forming an arch between the cups. Then do the same thing with the cups eight inches apart.
Materials: (all things you have at home...hint, hint)
2 cups erasers poster board ruler
a. The six inch arch can hold the most erasers. 0 friends thought this would be true.
b. The straight poster board holds the most erasers. 8 friends thought this would be true.
c. The eight inch arch holds the most erasers. 2 friends thought this would be true.
d. They all hold exactly the same amount of erasers. 4 friends thought this would be true.
Conclusion: The six inch arch can hold the most weight! We were proven wrong, but we learned a lot! One group's six inch arch held nine erasers and could have kept going. Here's why...2,000 years ago some really smart people changed the straight bridge into an arch shape in order to distribute weight better. A straight line has to hold weight all in one place. An arch sends weight back down the sides to the ground so the bridge is much stronger. We can't wait to go examine the Tiehack Bridge next week on our Buttermilk Hike (details coming soon)!
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