P2 Chapter 2: Energy Practice Flashcards

Vocabulary-style flashcards covering energy stores, transfer methods, temperature, power, and renewable/non-renewable resources based on the P2 Chapter 2 lecture notes.

Joule ($J$)

The standard unit of energy used to measure energy values in food, fuels, and stores.

Kilojoule ($kJ$)

A unit of energy equal to $1000\,J$.

Chemical Store

The energy store associated with food, fuels, batteries, and oxygen.

Kinetic Store

The energy store associated with moving objects.

Gravitational Potential Store

The energy store associated with an object's position in a gravitational field.

Elastic Store

The energy store associated with objects changing shape, stretching, or squashing.

Thermal Store

The energy store associated with hot objects; its size depends on temperature and the amount of material.

Law of Conservation of Energy

The law stating that energy cannot be created or destroyed, only transferred between stores.

Dissipated

A term describing energy that is transferred to the thermal store of the surroundings and effectively wasted.

Temperature

A measurement of how hot or cold something is, measured in degrees Celsius ($^{\circ}\text{C}$) using a thermometer.

Equilibrium

A state reached when two objects end up at the same temperature and no more energy is transferred between their thermal stores.

Conduction

The process where particles in a solid transfer energy by colliding with other particles when they vibrate.

Conductor

A material, such as metal, through which energy is transferred very quickly.

Insulator

A material (typically non-metals like wood, liquids, or gases) through which energy is transferred very slowly.

Convection

The process of energy transfer in liquids and gases where hotter, less dense regions rise and cooler, denser regions take their place.

Convection Current

The movement of particles in a liquid or gas that transfers energy throughout the medium.

Infrared Radiation

Energy that travels as waves and does not need particles to move; it can travel through empty space or a vacuum.

Vacuum

A space containing no particles, such as the space between the Sun and the Earth.

Thermal Imaging Camera

A device that detects infrared radiation and produces a false-colored image where redder areas indicate higher temperatures.

Power

The rate of transfer of energy, calculated using the formula: $\text{power (W)} = \frac{\text{energy (J)}}{\text{time (s)}}$.

Watt ($W$)

The unit of power, representing energy transferred per second.

Kilowatt ($kW$)

A unit of power equal to $1000\,W$; for example, a traditional oven has a power of about $12\,kW$.

Kilowatt hour ($kWh$)

The unit of energy used by electricity companies to calculate bills based on the power of appliances and the number of hours used.

Energy Resource

Material or natural process used to heat homes, power appliances, or move people.

Fossil Fuel

Non-renewable energy resources such as coal, oil, and gas formed over millions of years from fossilised remains.

Non-renewable

An energy resource that cannot be easily replaced once it runs out.

Renewable

An energy resource that will not run out, such as wind, tidal, wave, solar, biomass, or geothermal energy.

Thermal Power Station

A facility that burns fossil fuels to heat water and produce steam to drive a generator.

Turbine

A device, similar to a big fan, driven by steam or water that subsequently drives a generator.

Generator

A machine driven by a turbine that provides the push to make an electric current flow.