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Science Launch G4 / Week 04 / Thursday
4/6
Week 04 · Energy Converter

Thursday

Think like an engineer
// Design a device that changes energy
⏱ about 15 min

Thursday: Think like an engineer

Rocket's comeback roller only rolls back halfway. "I will just add five more rubber bands!" he says.

Raven holds up the bag. "We only have two left. What do you notice about our supplies?"

Rocket frowns, then laughs. "Okay. I cannot use what I do not have."

Nova projects a checklist in glowing letters. "Would you like a hint? Write what a good roller must do. Then write your limits."

Criteria and constraints

Engineers solve problems by designing things. Before they build, they list criteria and constraints.

Criteria are what the design must do to be a success. Example: the roller must come back at least 1 meter.

Constraints are the limits. Examples: only three rubber bands, only things at home, only 20 minutes.

Engineers compare different designs by checking how well each one meets the criteria.

Part of Rocket's planIs it a constraint (a limit)?
We only have three rubber bands.?
The roller must come back at least 1 meter.?
We have 20 minutes to build.?
The roller must not hit the walls.?
WHY THIS EXERCISESorting goals from limits helps engineers plan a design that can really work.

Rocket and Raven test two designs. Read their results.

DesignWeight insideCame back (cm)
Design Atwo washers40
Design Bfive washers110
COMPARE THE DESIGNS
  • Read the question.
  • Tap your answer.
The criterion is: come back at least 100 cm. Which design meets it?
AN ENGINEER'S STEPS
  • ?Define the problem with criteria and constraints
  • ?Brainstorm ideas
  • ?Build a design
  • ?Test it
  • ?Improve it and test again
WHY THIS EXERCISEEngineers repeat test and improve until the design meets the criteria.

Reading test results

Design B had five washers and came back 110 centimeters.

Design A had two washers and came back 40 centimeters.

Only the weight changed, so the weight made the difference.

Engineers keep the change that helps and test again.

ENGINEER CHOICES
  • Read the question.
  • Tap your answer.
How much farther did Design B come back than Design A?
What was the one change between Design A and Design B?
Which design would an engineer keep?
Goals a design must meet are ____.
Limits on a design are ____.
StatementTrue or false?
Engineers test and improve designs more than once.?
Time can be a constraint.?
A criterion is a limit on supplies.?
WHY THIS EXERCISEEngineers set goals and limits, then test and improve.
Design A came back 40 cm. Did it meet a 100 cm criterion? Type yes or no.
WHY THIS EXERCISE40 is less than 100, so Design A did not meet the criterion.

You planned like a pro today. Tomorrow we visit giant energy converters that make electricity.

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