Vocab
What do engineers call a model of a possible solution that can be tested?
What is a prototype?
What is the first step in the engineering design process?
Identify/define the problem/need
A paper tower must stand at least 30 cm tall. Is this a criterion or a constraint?
What is a criterion?
Why do engineers test prototypes?
To see if they work
How can engineers fairly compare two bridge designs?
Test them under the same conditions
What are the specific requirements a successful design must meet called?
What are criteria?
Why do engineers research a problem?
To gather information
Students have only 20 minutes to build a bridge. Is this a criterion or a constraint?
What is a constraint?
A bridge holds 10, 12, and 14 coins in three trials. What is the average?
12 coins
Why isn't a design's appearance enough to prove it works?
It needs test evidence
What do engineers call limitations such as cost, time, materials, or size?
What are constraints?
What should engineers do before choosing a design?
Compare possible solutions
A school needs a ramp that allows wheelchair users to enter a building safely. Identify one possible design criterion.
The ramp must provide safe, accessible entry; an acceptable slope is another criterion.
Tower A holds 15 books. Tower B holds 22. Which is stronger based on this test?
Tower B
Three filters remove 60%, 85%, and 72% of particles. Which filter works best?
The filter that removes 85%
What is the process of making changes to a design to improve its performance called?
What is iteration?
What should engineers do when a prototype fails a test?
Improve or redesign it.
A team must build a bridge that holds 2 kg using no more than 30 craft sticks. Identify one criterion and one constraint.
Criterion: the bridge must hold 2 kg. Constraint: no more than 30 craft sticks may be used.
Why should engineers change only one variable at a time when testing?
To identify what caused a change
Why isn't a failed prototype necessarily a failure of the whole project?
Engineers can use results to improve it.
An engineer chooses a bridge design that meets the requirements while using the fewest materials possible. What is the process of improving a design to achieve the best performance under given limitations called?
What is optimization?
Why do engineers test a prototype more than once?
To improve the design
A prototype meets the strength requirement but exceeds the budget. Has it met all the requirements for a successful solution? Explain.
No. It meets the strength criterion but violates the budget constraint, so the team must revise or select another design.
A bridge holds 18 N, 20 N, and 19 N in three trials. What is the range of its results?
2 N
A shelter must withstand 90 km/h winds and cost no more than $600. Shelter A withstands 80 km/h and costs $500. Shelter B withstands 100 km/h and costs $700. Does either meet both requirements?
No. A is too weak; B costs too much