Who Will Break Under Pressure?

Sixth, Seventh, and Eighth Grade Physics Science Fair Project
Photo Source: mainelytrusses.com

Interested in physics and engineering? Check out this great science fair project completed Selah School District sixth grader, Scotty G. The roof truss system is a crucial part in the home construction process with the truss type used largely affected by the roof span, calculated weight load {taking into consideration both the weight of the materials used and the projected snow drifting}, and wind load or the pressure a roof must endure when the wind is blowing against it. After researching roof structure, Scotty was interested in finding out, all else being equal, which type of truss - the Graf-post, King-post, and Queen-post trusses - would hold the most mass before breaking under the pressure.

Making models of all three truss types from thin balsa wood, Scotty used a Vernier force plate to measure the Newtons of force sustained by each model before they failed. [NOTE: We weren't familiar with the technology and upon further investigation, noticed that it can be quite pricey. Selah School District sixth grader, Camdon A., did a similar project, but used another method to measure the force sustained. You may wish to check out his project for a more affordable method of measure!]

For the full project write-up, including the experiment design and results, be sure to visit Scotty's project page!