Feeling Forces – Making Bridges with Kids
Static forces are not visible and students were clearly guessing about which was where in pictures of bridges. To linking the concepts of compression and tension to something they will always remember is the challenge. Here are the diagrams they worked off of:
So we had them make arch and suspension bridges from their own bodies with a small kid on top for the ‘load’. Very fun, sort of chaotic but with great pics to show for it. If you want to do this with your students, the plan is below the pics.
Started the day with a pretty open-ended assignment to come up with a way to do this in boy teams and girl teams (to avoid um, problems :-)) Great with well-behaved classes, kids lost the plot in more crazy ones.
By the end of the day, it was much more efficient and I think fun, for them to look at pics of kids from last year doing this, guess which kind of bridge they were modeling, then decide who would be each piece of the bridge – load, pillars and anchors. 5 students per bridge worked very well. Each team modeled suspension, arch and beam bridges and had their pic taken when done. I uploaded their pics onto my photo site with a private link so they could look at each other and have a laugh. It was a fun and quick way to celebrate their success. Then some groups did pyramids just because.
SAFETY ISSUES: Supervise closely to make sure students don’t jump on each other’s backs. Do this on a soft surface. The suspension and arch bridges are a little safer if done on knees instead of standing. And give a day warning so girls can wear shorts or pants instead of skirts.