A Physics Bridge Building Contest
There are several examples (here, here, and here, for example) of webpages that provide outlines and results of various balsa wood bridge contests being run around the country. The particular contest that I ran this year is a continuation of a contest started by Dave Vernier (with help from my father, Walter Hellman) at Hillsboro High School in the mid 1970's. The rules and requirements for my contest closely adhere the original rules. However, the bridge tester I built for the contest utilizes new technology (from Vernier Software and Technology) that makes constructing the bridge tester a far simpler proposition than it was 20+ years ago.
It's my hope that these pages will help other physics teachers implement this same contest in their classes. I've included course handouts, pictures and technical schematics for each aspect of the project in PDF format. This is a project that sparks interest in physics, engineering and architecture and encourages students to pursue careers in these fields. My first contest ran this year at Elmira High School outside Eugene, Oregon. The contest ran in my junior/senior physics class with extra-credit opportunities for the freshmen in my physical science classes. Feel free to e-mail me with any questions.
The Bridge Tester: This will provide a means to test both the miniature bridges (16-cm) as well as the full-size (38-cm) bridges. Uses a Vernier Software and Technology force plate interfaced to a computer to measure the magnitude of the force applied to a bridge that causes it to break.
The Electronics/Computer Interface: Here you'll find a description of the electronics used in the contest as well as the Experiment file that I used in Logger Pro 3
Miniature Trusses: These serve a dual purpose- providing the first competitive event of the contest and also introducing students to the new skills of cutting, gluing and sanding balsa wood.
Mini-Bridges: Here, the students get exposure to the difficulties associated with completing a full bridge. Connecting two trusses to make a complete bridge proves more difficult than one might expect. Before launching into full-scale bridge construction, students learn that special care must be taken to ensure both sides of the bridge are nearly identical.
Full-Scale Bridges: Students put together all of their developed knowledge about bridges to create the strongest possible bridge using only 45 grams of material (wood and glue).