Compare Engineering Solutions
Grade 4 - Science - Building Confidence
Problem: a paper bridge must hold 20 washers. Which solution best fits the criteria and constraints?
- fold the paper into beams before taping it
- stretch light-colored fabric over the thermometer area
- assign a different short-long flash pattern to each message
- coat the envelope with wax paper
Which criterion should be used to compare solutions for this problem: a wind barrier must stop soil from blowing away?
- uses ten craft sticks
- lowers the temperature by at least 5 degrees
- keeps most sand in the tray
- no water reaches the seeds
Which constraint must the design team consider for "a model roof must drain rainwater away from a doorway"?
- uses only short and long flashes
- uses one plastic sheet and four straws
- uses one square meter of fabric
- uses one envelope and one coating material
Evidence: close sticks lost less sand than wide gaps. Which solution comparison is best supported?
- seal the envelope edges with tape
- keep the folded beams and strengthen the center span
- make the side channel deeper
- reduce gaps between the sticks
Why compare more than one solution for "a model roof must drain rainwater away from a doorway"?
- criteria do not matter after testing
- different designs may meet the criteria and constraints with different tradeoffs
- evidence makes solutions impossible
- constraints should be ignored
Problem: a wind barrier must stop soil from blowing away. Which solution best fits the criteria and constraints?
- coat the envelope with wax paper
- fold the paper into beams before taping it
- place sticks close together across the windy side
- slope the sheet toward a side channel
Which criterion should be used to compare solutions for this problem: a model roof must drain rainwater away from a doorway?
- holds at least 20 washers
- keeps the doorway area dry
- keeps most sand in the tray
- no water reaches the seeds
Which constraint must the design team consider for "a shade cover must cool a playground thermometer"?
- uses one square meter of fabric
- uses one envelope and one coating material
- uses ten craft sticks
- uses only two sheets of paper and tape
Evidence: the side-channel roof kept the doorway dry twice. Which solution comparison is best supported?
- seal the envelope edges with tape
- tilt the fabric to block afternoon Sun too
- make the side channel deeper
- add longer pauses between messages
Why compare more than one solution for "a wind barrier must stop soil from blowing away"?
- evidence makes solutions impossible
- different designs may meet the criteria and constraints with different tradeoffs
- constraints should be ignored
- the first design is always best