What is a prototype?
A model or early version of a design used for testing
What is a constrain in engineering?
A limit on a design, such as a cost, time, size or available material
Why should scientists keep most conditions the same during a test?
To make a fair comparison and know what caused differences in results.
Which material is generally better for a raincoat: paper or waterproof plastic?
waterproof plastic because it resists water.
Why do engineers record the results of their tests?
To compare designs, identify problems and make improvements
test how much it weighs or how comfortable it is
a doghouse must keep a dog dry. Is keeping the dog dry a criterion or a constraint?
Criterion.
Two groups test different paper towels. One uses a cup of water and the other uses two cups. What is wrong with the test?
They used different amounts of water, making the test unfair.
A student wants to pick up scattered steel paper clips without touching them. What tool could help?
a magnet
A machine packages 8 boxes per minute. Another packages 12. Which is faster?
The machine packaging 12 boxes per minute
A student builds a toy car, but its wheels keep falling off. What should the student do next?
Improve how the wheels are attached and try again.
A student must built a toy using only paper, tape and string. Identify the constraints.
The materials are limited to paper, tape and string.
Students compare three toy boats. Name two conditions they should keep the same.
Same amount of weight, water conditions or testing method
A garden sign must stay outdoors for months. Name two important properties of its materials.
weather resistance and strength or durability
A class tests three towers. Tower A holds 4 blocks, Tower B holds 7 and Tower C holds 5. Which is strongest? How many more blocks does it hold than Tower A?
Tower B. It holds 3 more blocks than Tower A
A paper bridge colapses under three books. Name two changes that might make it stronger.
A class wants a bridge that holds 10 toy cars, costs less than $20 and looks colorful. Which requirement matters most for the bridge's main purpose?
Holding 10 toy cars
Two thermometers are tested in different rooms at different times of the day. Students want to know which is more accurate. What should they change about the test?
Test both in the same location at the same time of the day
A student builds a floating raft. Which is a better choice: a solid rock slab or lightweight foam? Explain
lightweight foam because it is buoyant and floats more easily
A farmer wants to plan seeds in straight rows across a large field. Name one technology that could help.
modern plant seeder, Gps guided planting equipment.
An engineer improves a design and tests it once. It works! Why might the engineer still test it again?
To make sure the design works consistently and reliably.
Two designs both work. One costs $18 and one costs $26. The budget is $20. Which design can be chosen and why?
The $18 design because it works and meets budget constraints.
A team tests two model parachutes, but one carries a heavier toy. Explain why the results cannot fairly show which parachute design works better
Different weights could affect falling speed. Both parachutes should carry equal weights and be dropped from the same height.
A student wants to move a heavy box into a truck. How could a ramp help?
A ramp allows the box to be moved upward with less force over a longer distance
Three fans are compared. Fan A costs $15 and cools one room. Fan B costs $8 and two are needed per room. Fan C costs $25 and cools two rooms. You need to cool two rooms for under $30. Which is best? Explain.
Fan C. It costs $25 and cools both rooms while staying under budget.