A class must build a bridge that holds at least 2 kg, costs no more than $15, uses only straws and tape, and is finished in 40 minutes. Which requirement is a criterion the finished bridge must achieve?

A team designs a water filter that must remove at least 90% of the sediment, using only $8 of materials and one 30-minute class period. Which requirement is a constraint on the design?

In engineering design, what does the word constraint mean?

In engineering design, what does the word criterion mean?

A cooler must keep ice frozen for 4 hours, have a mass under 250 g, and cost under $12. A team's cooler keeps ice frozen 6 hours, has a mass of 300 g, and cost $9. Why does this design fail?

Goal: a wind turbine that lifts at least 100 g, costs under $5, and uses 4 blades or fewer. A: lifts 120 g, $4, 3 blades. B: lifts 150 g, $7, 4 blades. C: lifts 80 g, $3, 4 blades. D: lifts 130 g, $4, 6 blades. Which design succeeds?

A team may spend no more than $20 on materials for its model car. That $20 limit is a constraint on the design problem.

A team makes a boat hull thicker. The hull now carries 250 g instead of 180 g, but its own mass rises from 40 g to 90 g, close to the 100 g limit. What is this gain paired with a loss called?

Before building, a team builds a small rough model of its shelter to gather test data on how much wind it survives. What is that early model called?

A team tests its parachute, uses the fall-time data to widen the canopy, tests again, then widens it once more. What is this repeating cycle of test, change, and test again called?

A team changes its insulated cup so it keeps the drink warm longer while still using under $6 of materials. What word names this work of improving a design without breaking its limits?

After testing three cart designs, a team keeps Cart A's wheels because they rolled smoothest and Cart B's frame because it was lightest, then builds one new cart using both parts. What is this process called?

A teacher writes the design problem as "build a good phone stand." A student rewrites it so it can be judged by evidence. Which rewrite states a testable criterion?

A team's greenhouse design must raise the inside temperature by at least 5 degrees Celsius, and the teacher adds: use only materials from the recycling bin. What has the teacher added?

Two model cars must travel at least 3 meters. Car A goes 4.2 m but cost $18 against a $10 budget. Car B goes 3.4 m and cost $7. Which car should the team submit, and why?

A team's prototype hand cart carries the required 5 kg but tips over on the ramp during two of three trials. What is the best next step in the design process?

Why do engineers write down the criteria and constraints before they start building a solution?

Three prototype shelters must survive wind from a fan. To compare them fairly, what should the team keep the same for every prototype?

A school asks for a bike rack that holds at least 8 bikes, fits in a space 4 meters wide, costs under $600, and is installed before the term ends. Which item on that list is a criterion rather than a constraint?

A team's egg-drop design protects the egg from a 2-meter fall, but the rules say no glass may be used and the team taped a glass jar inside. What is wrong with this solution?