Fall SAVY 2013, Week 6 – Engineering the World (3rd/4th grade)
What a great final day of Engineering the World! Before we jumped into our final projects, students created a concept map (an organized brainstorming tool) of everything they now knew about materials. I was happy to see new content as well as more complex connections appear than the first time we made concept maps.
Before parents visited, we were able to try one last engineering challenge and to get our potato battery working! The new engineering challenge was to create a structure that was at least 6″ tall and could hold the most magazines without letting them touch the table/floor. This challenge was trickier than the boat challenge because we had limited materials; each student was provided with one magazine and 3.5′ Scotch tape. There were a wide range of designs, from towers to pillow-like mounds. While not all structures were quite 6″, some held so much weight that we ran out of magazines to add!
Students then gathered around the center table and helped connect our potato pieces together. The problem with the last attempt was that the galvanized nails were not sufficient conductors. Thus, while they provided the necessary zinc, they prevented the current from flowing. However, using galvanized fencing nails solved this problem. We also used thicker copper wire and 5 potato pieces to increase our voltage. We noticed that while the potatoes could illuminate the red LED and the dual-color LED, the voltage was not sufficient to illuminate the small lamp. While we did not demonstrate this, many other materials can be substituted for potatoes, such as lemons, apples, and even gatorade.
Once the parents arrived, students had a great time teaching them about the potato battery and the pH measurements, and showing them the boats they had created and their structures from earlier in class. I hope the curiosity and willingness to take risks they have demonstrated in the past month and a half continues to lead them toward interesting problems and unique solutions. Best of luck, and I hope to see you again in another SAVY class!