Engineering Design Challenges — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Picking the best idea from a brainstorm uses your criteria.
Criteria let engineers measure each idea against the same target goals.
2. An idea that costs less but breaks faster has a clear trade-off.
Trade-offs appear whenever gaining one feature means losing another feature.
3. A bridge using cardboard is light, but it is not very strong.
Cardboard fails under big loads, showing strength as a trade-off for lightness.
4. Brainstorming works best when teams write down many ideas.
Many ideas raise the odds that at least one design fits all the criteria.
5. An airplane with heavy clay flies short but very straight.
Extra weight steadies flight but cuts distance, which is a classic trade-off.
6. A water filter with small holes cleans well but slows the flow.
Smaller openings trap more particles but reduce how fast water drips through.
7. A marble run with tight turns is exciting but loses speed.
Tight turns add friction, so speed drops while excitement and control rise.
8. Engineers choose the design that best meets goals and limits.
The winning design balances every criterion against every real constraint.
9. Two solutions compared on a chart help show every trade-off.
Charts line up features so engineers can compare options at a glance.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Cheaper materials
→ Lower cost but weaker build
Lower cost but weaker build
Wider airplane wings
→ Steadier flight but slower speed
Steadier flight but slower speed
Smaller filter holes
→ Cleaner water but slower flow
Cleaner water but slower flow
Tight marble track turns
→ More excitement but lower speed
More excitement but lower speed
Each choice gains one feature while giving up another, showing classic trade-offs.