http://www.teachengineering.org/view_lesson.php?url=collection/cub_/lessons/cub_mechanics/cub_mechanics_lesson10.xmllessontext/xmlIntegrated Teaching and Learning Program, mechanicsbendingtensioncompressiontensileforcesstructuresbridgessky scraperbeamTension CompressionBendingNeutral axis

To introduce the two types of stress that materials undergo — compression and tension — students examine compressive and tensile forces and learn about bridges and skyscrapers. They construct their own building structure using marshmallows and spaghetti to see which structure can hold the most weight. In an associated literacy activity, students explore the psychological concepts of stress and stress management, and complete a writing activity.

Engineers consider tension and compression forces when designing a building or structure for our everyday safety, comfort and convenience. Human-made structures include homes, skyscrapers, subways, bridges, tunnels and dams, as well as products such as pens, bungee jumping rope, washing machines, wheelchairs, moon rovers, prosthetic legs or bookshelves, to name a few. Engineers use complex mathematical models to predict the expected loads on these structures and products. They determine suitable material components to support the anticipated forces. Recognize that compression and tension forces are important considerations in building structures.Understand that the weight a building can hold is dependent on the design of the building.Understand that certain materials are good at resisting tensile forces and others are good at resisting compressive forces.Realize that buildings fail when engineers do not use designs and materials that are strong enough to resist compressive and tensile forces. 50TeachEngineering.orgChris YakackiBen HeavnerMalinda Schaefer ZarskeDenise Carlsonhttp://www.pbs.org/wgbh/buildingbig/wonder/structure/golden_gate.htmlMacaulay, David. Building Big. Boston, MA: Houghton Mifflin Company, 2000.http://gocalifornia.about.com/cs/sanfrancisco/a/ggbridge_3.htmhttp://www.infoplease.com/ipa/A0001326.htmlS11417ADInternational_Technology_Education_Association-ITEA_STL_StandardsTechnologyI. Buildings generally contain a variety of subsystems.68S11424D2ColoradoSciencea. Predict and evaluate the movement of an object by examining the forces applied to it 88S11425BDColoradoScienceb. Describe methods and equipment used to explore the solar system and beyond 88United StatesCopyright 2012 - Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulderhttp://www.teachengineering.org/policy_ipp.phphttp://www.teachengineering.org/2010-08-238Teacher