C

We concluded our structural/civil engineering unit by having the students build bridges. The test was that a small lego car had to be able to drive across the bridge spanning two chairs about 18 inches apart. We again had the students draw out their plans first before getting any materials.

The materials included construction paper, popsicle sticks, tape, rubber bands, paper clips, etc.

Only a few of the pairs were able to build successful bridges. Many students did not find a way to ensure internal strength at the middle of bridge, so the car often crashed after sagging the bridge. We debriefed by talking about what made the successful bridges successful. Emma also built an successful bridge in 10 minutes out of limited materials, which we also talked about.