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OpenStem
@openstem · Joined Jul 2026
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Flashcards8 cards
What is a scale drawing?1 / 8
A scale drawing shows something smaller or bigger than it really is, but keeps all the proportions the same, so the shape still looks correct.
Engineering · L2 · Reading a Scale
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Engineering · L2 · Reading a ScaleFlashcards8 cards
What is injection molding?1 / 8
Injection molding is a way of making plastic parts. Plastic pellets are melted, then pushed under pressure into a hollow metal mold shaped like the part.
Engineering · L2 · Molding and Casting
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Engineering · L2 · Molding and CastingFlashcards7 cards
What is cutting or machining?1 / 7
Cutting (machining) shapes a solid piece of material by removing bits of it — for example carving wood with a chisel or cutting sheet metal with shears.
Engineering · L2 · Cutting, Machining, and Mass Production
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Engineering · L2 · Cutting, Machining, and Mass ProductionFlashcards9 cards
How do you calculate a gear ratio?1 / 9
Gear ratio = teeth on the driven gear ÷ teeth on the driving gear. The driving gear is the one turned by the motor or your hand; the driven gear is the one it turns.
Engineering · L2 · Gear Ratios
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Engineering · L2 · Gear RatiosFlashcards10 cards
What three parts does every lever have?1 / 10
A fulcrum (the fixed pivot point), an effort (the force you apply), and a load (the weight or resistance you are trying to move).
Engineering · L2 · Levers: Three Classes
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Engineering · L2 · Levers: Three ClassesFlashcards8 cards
What class of lever is a nutcracker?1 / 8
Class 2. The hinge at the far end is the fulcrum, the nut sits between the hinge and your hands, and your hands supply the effort at the open end.
Engineering · L2 · Matching Tools to Lever Classes
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Engineering · L2 · Matching Tools to Lever ClassesFlashcards9 cards
What shape is an arch?1 / 9
An arch is a curved structure that spans an opening, like a doorway or a gap between two supports. Instead of a flat top, its top follows a smooth curve.
Engineering · L2 · Arches & Domes
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Engineering · L2 · Arches & DomesFlashcards10 cards
What does it mean to connect batteries in series?1 / 10
Connecting batteries in series means joining them end to end, positive to negative, in a single chain — like two AA batteries stacked inside a flashlight.
Engineering · L2 · Batteries in Series vs Parallel
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Engineering · L2 · Batteries in Series vs ParallelFlashcards10 cards
What three parts does a simple robot combine?1 / 10
A robot combines sensors (to sense the world), a simple program (to decide what to do), and motors or actuators (to act) — sense, decide, act.
Engineering · L2 · Simple Robots & Motors
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Engineering · L2 · Simple Robots & MotorsFlashcards6 cards
What is a simple rule a robot's program might follow?1 / 6
"If the front sensor detects an obstacle close by, then stop the motors and turn." Simple robot programs are often built from rules just like this one.
Engineering · L2 · Robot Programs & Simple Rules
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Engineering · L2 · Robot Programs & Simple RulesFlashcards9 cards
What is density, in simple terms?1 / 9
Density is how much mass is packed into a given volume — how 'heavy for its size' something is. A denser liquid has more mass squeezed into the same amount of space than a less dense liquid.
Engineering · L2 · Density Layers in Liquids
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Engineering · L2 · Density Layers in LiquidsFlashcards8 cards
What does it mean for an energy source to be 'renewable'?1 / 8
A renewable energy source is one that naturally refills itself and does not run out — like sunlight, wind, and moving water. The sun keeps shining and the wind keeps blowing no matter how much we use.
Engineering · L2 · Renewable Energy Basics
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Engineering · L2 · Renewable Energy BasicsFlashcards6 cards
Why do engineers study weather data before building a solar farm?1 / 6
Solar panels only make a useful amount of electricity where there is plenty of direct sunlight. Engineers check years of sunshine data to pick a site that stays sunny most of the year.
Engineering · L2 · Placing Solar Panels and Wind Turbines
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Engineering · L2 · Placing Solar Panels and Wind TurbinesFlashcards10 cards
What is a material life cycle?1 / 10
The full path a material takes: it starts as a raw resource, gets manufactured into a product, is used, and finally reaches its end of life — recycled, reused, or thrown away.
Engineering · L2 · Recycling & Material Life Cycles
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Engineering · L2 · Recycling & Material Life CyclesFlashcards10 cards
What does a mechanical engineer design?1 / 10
Machines and moving parts — engines, gears, robots, car suspensions, and anything with parts that push, spin, or slide.
Engineering · L2 · Engineering Disciplines
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Engineering · L2 · Engineering DisciplinesFlashcards10 cards
What is a pulley?1 / 10
A wheel with a groove around its rim that a rope runs over. It lets you change the direction of a pulling force, and sometimes reduce how much force you need.
Engineering · L2 · Pulleys & Mechanical Advantage
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Engineering · L2 · Pulleys & Mechanical AdvantageFlashcards10 cards
A single fixed pulley lifts a 60 N crate. How much pulling force is needed (ignoring friction)?1 / 10
60 N. A fixed pulley has MA = 1, so the effort force always equals the load's weight — only the direction changes.
Engineering · L2 · Pulleys & Mechanical Advantage — Worked Numbers
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Engineering · L2 · Pulleys & Mechanical Advantage — Worked NumbersFlashcards9 cards
What is friction?1 / 9
Friction is a force that resists the relative motion between two surfaces that are touching. It always acts opposite to the direction of motion, or attempted motion.
Engineering · L2 · Friction Basics
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Engineering · L2 · Friction BasicsFlashcards9 cards
Why might an engineer want to reduce friction inside a machine?1 / 9
Less friction means less energy wasted as heat, less noise, and less wear on the moving parts — so the machine runs more efficiently and lasts longer.
Engineering · L2 · Designing With Friction
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Engineering · L2 · Designing With FrictionFlashcards9 cards
Why do engineers draw circuits with symbols instead of photos of real wires and parts?1 / 9
Symbols are quick to draw, easy to read, and mean the same thing to every engineer everywhere — no matter what the real battery or bulb actually looks like.
Engineering · L2 · Circuit Diagram Symbols
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Engineering · L2 · Circuit Diagram SymbolsFlashcards8 cards
What does 'tracing' a circuit diagram mean?1 / 8
Following the path of the wires with your eye or a finger, component by component, to work out how current would flow and what would happen.
Engineering · L2 · Tracing a Schematic
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Engineering · L2 · Tracing a SchematicFlashcards9 cards
What is an electromagnet?1 / 9
A magnet made using electricity — a coil of wire wrapped around a core (usually iron) that only acts like a magnet while an electric current is flowing through the wire.
Engineering · L2 · Electromagnets
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Engineering · L2 · ElectromagnetsFlashcards8 cards
How does an electric motor use an electromagnet?1 / 8
A motor uses a coil that becomes an electromagnet when current flows. Its magnetic field pushes and pulls against another magnet, and that push-and-pull spins a shaft — turning electrical energy into motion.
Engineering · L2 · Electromagnets
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Engineering · L2 · ElectromagnetsFlashcards9 cards
What are the three ways heat can travel from one place to another?1 / 9
Conduction (through direct contact), convection (carried by a moving fluid), and radiation (as electromagnetic waves).
Engineering · L2 · How Heat Travels
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Engineering · L2 · How Heat TravelsFlashcards9 cards
Why does hot air rise inside a room?1 / 9
Heating makes air expand, which makes it less dense than the cooler air around it. Less dense air floats upward, the same way a less dense object floats in water.
Engineering · L2 · How Heat Travels
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Engineering · L2 · How Heat TravelsFlashcards9 cards
What is Pascal's principle, in plain terms?1 / 9
Pressure applied anywhere to a liquid sealed inside a closed system pushes out equally in every direction, reaching every part of the liquid and every surface it touches.
Engineering · L2 · Hydraulics
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Engineering · L2 · HydraulicsFlashcards9 cards
What is the basic rule for force multiplication in a hydraulic system?1 / 9
The pressure is equal on both sides, so force out ÷ area out = force in ÷ area in. Rearranged: force out = force in × (area out ÷ area in).
Engineering · L2 · Hydraulics — Force Multiplication by the Numbers
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Engineering · L2 · Hydraulics — Force Multiplication by the NumbersFlashcards9 cards
Why do engineers carefully study things that broke, instead of just replacing them and moving on?1 / 9
So they can find out exactly why it failed and change future designs or rules, preventing the same failure from happening again — possibly in many other structures, not just the one that broke.
Engineering · L2 · Learning From Failures
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Engineering · L2 · Learning From FailuresFlashcards8 cards
What three questions does a 'failure detective' process ask about an engineering failure?1 / 8
Investigators work through three steps in order:
Engineering · L2 · Learning From Failures
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Engineering · L2 · Learning From FailuresFlashcards10 cards
What does it mean for a bolt to be a "standard" size?1 / 10
Its dimensions — thread size, spacing, head shape — match an agreed rulebook that every manufacturer builds to, so a bolt from one factory fits a nut from a completely different factory.
Engineering · L2 · Standards & Codes
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Engineering · L2 · Standards & Codes