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OpenStem
@openstem · Joined Jul 2026
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Flashcards8 cards
Why does a raincoat keep you dry in the rain?1 / 8
A raincoat is made from a waterproof material. Rain slides right off it instead of soaking through to your clothes.
Engineering · L1 · Dressing for Weather
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Engineering · L1 · Dressing for WeatherFlashcards8 cards
Can one person build a whole playground alone?1 / 8
Usually not! A playground needs many hands and many kinds of thinking, so a team of people builds it together.
Engineering · L1 · Teamwork in Engineering
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Engineering · L1 · Teamwork in EngineeringFlashcards8 cards
What is a prototype?1 / 8
A prototype is a first try — a small, cheap model you build to test an idea before making the real, expensive version.
Engineering · L1 · Prototypes & Model Building
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Engineering · L1 · Prototypes & Model BuildingFlashcards9 cards
Why is it easier to push a wagon on wheels than to drag the same wagon on its side?1 / 9
Wheels roll instead of scraping along the ground. Rolling has much less friction than sliding, so it takes far less push to move the same load.
Engineering · L1 · Wheels & Axles
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Engineering · L1 · Wheels & AxlesFlashcards9 cards
What is a ramp (also called an inclined plane)?1 / 9
A ramp is a flat surface that slopes from low to high. It's one of the simplest machines — it lets you push something up instead of lifting it straight up.
Engineering · L1 · Ramps & Wedges
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Engineering · L1 · Ramps & WedgesFlashcards9 cards
What is an electrical conductor?1 / 9
A material that lets electricity flow through it easily. Metals like copper are good conductors.
Engineering · L1 · Conductors & Insulators
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Engineering · L1 · Conductors & InsulatorsFlashcards9 cards
What does a magnet do?1 / 9
A magnet pulls certain metals toward it — like iron and steel — without even touching them. This pull is called attraction.
Engineering · L1 · Magnets
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Engineering · L1 · MagnetsFlashcards9 cards
Does air take up space, even though you can't see it?1 / 9
Yes! Air is real stuff, made of tiny gas particles. It takes up space just like water or sand does — you just can't see it.
Engineering · L1 · Air Takes Up Space
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Engineering · L1 · Air Takes Up SpaceFlashcards9 cards
What is wind?1 / 9
Wind is just air that is moving. You cannot see it, but you can feel it push against your skin, your hair, and things around you.
Engineering · L1 · Wind & Sails
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Engineering · L1 · Wind & SailsFlashcards10 cards
What does it mean to 'count the cost' of a project?1 / 10
It means adding up how much money all the parts and supplies cost, so you know the total price before you start building.
Engineering · L1 · Counting the Cost
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Engineering · L1 · Counting the CostFlashcards9 cards
What is a design notebook?1 / 9
A notebook where you write down and sketch your ideas, what you tried, and what happened — so you don't forget it later.
Engineering · L1 · Keeping a Design Notebook
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Engineering · L1 · Keeping a Design NotebookFlashcards10 cards
What is a lever?1 / 10
A lever is a stiff bar or board that can tip up and down around a fixed point. Pushing down on one end lifts the other end up.
Engineering · L1 · Levers & Seesaws
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Engineering · L1 · Levers & SeesawsFlashcards10 cards
What is a gear?1 / 10
A gear is a wheel with teeth around its edge. The teeth are what make gears special — they let one gear grab onto another gear and turn it.
Engineering · L1 · How Gears Turn Each Other
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Engineering · L1 · How Gears Turn Each OtherFlashcards10 cards
What does a light bulb do?1 / 10
It turns electricity into light. Electricity goes in, light comes out.
Engineering · L1 · Light Bulbs: Electricity Into Light
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Engineering · L1 · Light Bulbs: Electricity Into LightFlashcards9 cards
What does a buzzer do?1 / 9
A buzzer turns electricity into sound. Give it power, and a tiny part inside vibrates fast to make a buzzing noise.
Engineering · L1 · Sound Makers
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Engineering · L1 · Sound MakersFlashcards9 cards
Why does a hot air balloon rise into the sky?1 / 9
The burner heats the air inside the balloon. Heated air becomes lighter than the cool air outside, so the balloon floats upward — the same way a cork floats up through water.
Engineering · L1 · Hot Air Rises
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Engineering · L1 · Hot Air RisesFlashcards10 cards
What happens to water if you keep heating it on a stove?1 / 10
It boils! The water gets so hot it turns into steam, which is water as a gas.
Engineering · L1 · Water Turning to Steam
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Engineering · L1 · Water Turning to SteamFlashcards9 cards
What is a trade-off?1 / 9
A trade-off is when getting more of one good thing means you get less of another good thing. You can't always have everything at once.
Engineering · L1 · Trade-Offs
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Engineering · L1 · Trade-OffsFlashcards5 cards
What is compression?1 / 5
Compression is a pushing force. When you stand on a bridge, your weight pushes down and squeezes the material underneath.
Engineering · L2 · Bridges and Forces
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Engineering · L2 · Bridges and ForcesFlashcards5 cards
What is a gear?1 / 5
A gear is a wheel with teeth around the edge. When two gears mesh, turning one makes the other turn too.
Engineering · L2 · Gears, Pulleys, and Circuits
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Engineering · L2 · Gears, Pulleys, and CircuitsFlashcards8 cards
What does it mean for a material to be 'strong'?1 / 8
A strong material can carry a heavy load or be pulled hard without breaking or snapping.
Engineering · L2 · Strength and Flexibility
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Engineering · L2 · Strength and FlexibilityFlashcards7 cards
What is hardness, in engineering terms?1 / 7
Hardness is how well a material resists being scratched, dented, or worn away at its surface.
Engineering · L2 · Hardness and Choosing Materials
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Engineering · L2 · Hardness and Choosing MaterialsFlashcards9 cards
What is a truss?1 / 9
A truss is a framework built entirely out of straight members joined into triangles. Roofs, bridges, cranes, and towers all use trusses to stay strong while using less material.
Engineering · L2 · Trusses & Triangulation
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Engineering · L2 · Trusses & TriangulationFlashcards7 cards
What does a Warren truss look like?1 / 7
A Warren truss uses diagonal members that zigzag between the top and bottom chords, forming a row of equilateral-looking triangles, with no vertical members needed.
Engineering · L2 · Truss Shapes and Uses
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Engineering · L2 · Truss Shapes and UsesFlashcards10 cards
What is a sensor?1 / 10
A sensor is a device that detects something in the environment — like light, heat, sound, or motion — and turns it into information a machine can use.
Engineering · L2 · Sensors & Feedback
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Engineering · L2 · Sensors & FeedbackFlashcards6 cards
How does an automatic door know when to open?1 / 6
A motion sensor near the door detects a person approaching and sends a signal that tells the motor to open the door.
Engineering · L2 · Everyday Feedback Devices
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Engineering · L2 · Everyday Feedback DevicesFlashcards10 cards
What is pressure, in simple terms?1 / 10
Pressure is how hard a fluid pushes against the walls of whatever holds it. More pressure means a stronger push.
Engineering · L2 · Pressure & Fluids in Pipes
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Engineering · L2 · Pressure & Fluids in PipesFlashcards9 cards
Which way does heat naturally flow?1 / 9
Heat always flows from a warmer place to a cooler place, never the other way around, until both places reach the same temperature.
Engineering · L2 · Heat Transfer & Insulation
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Engineering · L2 · Heat Transfer & InsulationFlashcards7 cards
Name one everyday object that relies on insulation to work well.1 / 7
Many answers work: a thermos flask, an oven mitt, a winter coat, a cooler box, a house wall, a fridge.
Engineering · L2 · Heat Transfer & Insulation
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Engineering · L2 · Heat Transfer & InsulationFlashcards8 cards
Why do engineers draw a plan before they build something?1 / 8
A drawing lets everyone agree on the exact size and shape before any materials are cut. Mistakes on paper are cheap; mistakes after building are expensive.
Engineering · L2 · Drawing Views
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Engineering · L2 · Drawing Views