This year, a group of 8th graders is participating in an engineering competition, run by the folks who bring you E2K. The competition is called Set Cubed and our team of 6 students is working against schools from across the US in a year long design challenge. The challenge is to create a model system that will deliver cargo from a town on one hill to a neighboring town across a valley. In the valley, there is a third town that operates a small airport that needs to have open airspace for certain hours of the day. The goal is to lift as much cargo as possible using the provided motors and any machines you can build within budget.
In our first semester, students worked to gain the background understanding of force, work, energy, and mechanical advantage necessary to develop smart solutions to the challenge. They have spent the bulk of their time conducting two experiments and analyzing the data they have collected. The first experiment is to design a series of winches and to measure their efficiency as they lift an increasingly large load. Students needed to apply their knowledge of gear ratios, torque, gravitational force, and design to build strong structures out of lego and tetrix that will maximize the lifting power of the provided motor. They used an energy station to measure the energy going into the machine and to record the time each lift took. They are now in the midst of thinking about the patterns of efficiency of each machine for different amounts of cargo. The second experiment is to determine the maximum mass a train can pull up a hill as the slope is increased. These students have been drawing force diagrams to analyze what forces are at play and in what directions. They are accounting for friction, traction, and momentum as they predict when the train will not be able to lift even its own weight and what an ideal slope for any potential hill or ramp might be. Both groups are discovering that what an ideal machine is depends on many factors and all students are beginning to incorporate each and every piece as they brainstorm potential solutions to the challenge.
Students are engaging in high level physics. I haven't had conversations such as these since I tutored freshmen physics in COLLEGE! They are learning to support the theoretical conversations with experimental data. They are using drills and hardware to engineer strong machines, using spreadsheets to collect and graph data, and using sophisticated reasoning and persistence to troubleshoot any problems they encounter. They are also learning to work together, to support their ideas with evidence, and to make scientific arguments with clarity and conviction. We can't wait to start designing and building our solution to the problem presented!
