Engineering Design Challenges — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Jay's catapult shoots 20 cm. He wants more distance. Which change fits the goal first?
A) Pull the spoon back farther before release.
B) Use a much heavier marble than before.
C) Set the catapult on softer carpet flooring.
D) Block the spoon so it moves less now.
Greater pull-back stores more energy, so the marble usually launches farther forward.
2. Lily's boat sinks under 10 pennies. She raises the sides. Best fair test next?
A) Try heavier coins to push the limit higher.
B) Use the same pennies and same tub of water.
C) Move the boat to a faster, deeper river nearby.
D) Test it on dry land with no water around.
Same coins and water isolate the side height as the only changed variable.
3. Noah's parachute drops too fast. Which change fits his goal of slower drops?
A) Use a smaller, much tighter canopy.
B) Add many heavy washers under the chute.
C) Make the canopy wider with more air drag.
D) Cut several large holes through the middle.
A wider canopy catches more air, increasing drag and slowing the parachute down.
4. Eva's straw rocket flies crooked. Which improvement most likely fixes the flight path?
A) Use much shorter and softer straws each time.
B) Push less air through the launcher straw.
C) Launch it from a higher, tilted starting spot.
D) Add small balanced fins near the rocket base.
Balanced fins create stability, guiding air evenly so the rocket flies straighter.
Part B: Fill in the Blank
Write the correct answer on each line.
1. Using test data to guide changes is called evidence-based design.
Evidence-based design relies on real test results, not guesses, to drive improvements.
2. Two tests with one variable changed produce a fair comparison.
Fair comparisons isolate one variable so the cause of any change is clear.
3. An idea that fails a test still gives the team useful information.
Failed tests reveal weak points, helping engineers make better decisions next time.
4. Each trip through the design loop is called one iteration.
Iterations repeat the design cycle, with each pass building on earlier results.
5. A design that meets every criterion within all limits is the best solution.
The best solution balances every criterion while staying inside every real constraint.