Transcript Foundations of Technology Structural Efficiency

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