Electricity & Energy
Science FactEvery device in your forge runs on energy. Electricity is one of the most useful ways to move energy from one place to another.
What is electricity?
Atoms contain tiny particles called electrons, which carry a negative charge. When electrons flow through a material like copper wire, that flow is called an electric current. Materials that let electrons flow easily are conductors (metals); materials that block them are insulators (rubber, plastic).
Voltage, current and power
Voltage is the 'push' that moves electrons, measured in volts. Current is how many electrons flow per second, measured in amps. Power is voltage times current, measured in watts. A phone charger is about 20 watts; a hair dryer is about 1,800 watts!
Storing energy
Batteries store energy as chemical energy and release it as electricity. In a lithium-ion battery, lithium ions move between two sides while electrons travel through your device to do work. Energy density tells engineers how much energy fits in each kilogram.
Energy is never free
Energy can't be created or destroyed, only changed from one form to another. This is called conservation of energy. No machine turns 100% of its energy into useful work; the rest usually becomes heat.
- Energy source (core)
- Storage (battery/cell)
- Wires carry current
- Output (beam/motor)
- Waste heat
COOL REAL FACTS
- Lightning can carry about 30,000 amps.
- Electric eels can produce around 600 volts to stun prey.
- Signals in your nerves are electrical too!
SCIENCE FACT vs SCI-FI
Quantum Cores, Star Cores and Dark Matter Cells are made up. Real devices use batteries, generators or solar panels.
TRY IT (SAFELY!)
With an adult, make a lemon battery: push a copper coin and a galvanized (zinc) nail into a lemon and connect several lemons to light a small LED.
REAL ENGINEER TIP
Engineers always do an 'energy budget': where the energy comes from, where it goes, and how much is wasted.
PARTS THAT USE THIS IDEA
LESSON CHECK
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