Success in Failure: Engineering Physics Class Tests the Strength of Model Bridges

Recently, Prep School science teacher Nick Verga imparted an important lesson to his students during Engineering Physics: there can be great success in failure. “In the span of five minutes, my students watched weeks and weeks of work crumble before them. Although this may sound disastrous, destroying our projects was actually the point,” Mr. Verga, who is new to CGPS this year, explained. He explained the arc of the project for the Weekly: 

     "In my Engineering Physics class, students spent a month planning, designing, constructing and finally destroying model bridges constructed out of balsa wood. The goal was to build a bridge at a minimum cost and weight that can maximize a load -- in this case, increasingly-weighted buckets of sand. The students started with building a small scale model made out of paper — called a boom — to explore how objects bend and compress using principles of physics. 

We then learned to use bridge-designing software that modeled how bridges experience tension and compression. The students used these online designs to cut, glue and construct a real-life truss bridge. 

The bridge project was the culmination of a few units of study. Before we move into any building project in the class, we spend some time developing theory, which is the physics side of engineering physics). We spent a week studying Newton’s Laws, a set of scientific principles that describe how objects interact with each other through forces. We examined different types of forces that may impact bridges, including the gravitational and spring forces. The spring force is important because it helps us to model how members of our bridges compress and extend when bearing a load. If there is too great of a force, it will cause the member to experience a structural failure and collapse.

The project itself was inspired by technology classes I took while I was in school and which I wanted to recreate with my own students. This bridge design project also connected to civil engineering. Each student researched a bridge in New York City, which they used as inspiration for their design. We spent some time discussing the many forms bridges can take and how they each are crafted to best handle their load of pedestrians, cars and trains. After our bridges were destroyed, we spent a week discussing the many transportation systems of New York City, including public buses, the subway system, trains and private car use. 

All in all, the project took a month to research and complete. The students were thrilled to finally test the strength of their bridges after all of that hard work. We brought in food and hot chocolate as we placed buckets of sand on top of our bridges. All of bridge models held at least ten times their weight, if not more. Some bridges held over 70 pounds of sand! I had to find weights around the classroom to throw on to try and break them. 

This project has been one of the highlights of my first year here. I think my favorite aspect of this project was that despite having the same goal of constructing a bridge, every group or individual had a completely different design. It was wonderful to see a space where students’ creativity and originality could show itself as it did. I enjoyed walking around the classroom and checking in with each group as they explained each part of their design, synthesizing our physics theory and knowledge of civil engineering. I was extremely proud of my students.”