1. Structural Efficiency Foundations of Technology Structural Efficiency © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology Teacher Resource – Unit 2 Lesson 1

2. The BIG Idea Big Idea: The Engineering Design Process is a systematic, iterative problem-solving method that produces solutions to meet human needs and wants. © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

3. Who’s Stronger? Who’s stronger, the elephant or the ant? © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

4. Who’s Stronger? Asian elephants are often employed to lift thousands of pounds of timber for logging efforts. Yet, an ant is much stronger pound for pound. An ant can easily lift many times its own body weight due to their small size which creates a greater cross sectional muscle mass An ant is a more efficient worker © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

5. What is Efficiency? Efficiency is a ratio of your output versus your input Efficiency is the ratio of the resources developed versus the resource supplied. Basically, efficiency measures the extent to which your device is functioning in the best possible manner. © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

6. Structural Efficiency In structural engineering efficiency is measured as the weight being supported divided by the weight of the supporting structure. © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

7. Crane Boom Efficiency For our crane boom: Efficiency = the breaking weight the weight of the crane boom The units must be the same! They will cancel out! Efficiency is a unit-less number (a ratio) © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology