PESS1.4 Energy Flashcards

Energy

The ability to do work or make things happen, measured in joules (J).

Energy transfer

When energy moves from one place or object to another.

Kinetic energy

The energy of a moving object, measured in joules (J).

Gravitational potential energy (GPE)

The energy an object has because it is up high, measured in joules (J).

Elastic energy

Energy stored in something stretched or squashed, like a spring or rubber band, measured in joules (J).

Chemical energy

Energy stored in food, fuel, or batteries, that gets released in a reaction, measured in joules (J).

Conservation of energy

Energy can't be created or destroyed, it just changes form or moves somewhere else. The total amount always stays the same.

Mass

The amount of matter that is in an object, measured in kilograms (kg). Stays the same everywhere.

Weight

The force of gravity pulling on an object, measured in newtons (N). Changes depending on gravity, e.g. less on the Moon.

Friction

A force that slows things down when two surfaces rub together, turning kinetic energy into heat.

Work

Energy transferred when a force moves an object, measured in joules (J).

Power

How fast energy is transferred or work is done, measured in watts (W).

Air resistance

A type of friction from air pushing against a moving object, slowing it down.

Thermal energy

The energy a substance has because its particles are moving/vibrating, measured in joules (J).

Particle theory of matter

The idea that everything is made of tiny moving particles, and how they move/arrange explains solids, liquids and gases.

Heat transfer

Heat energy moving from a hotter place to a cooler place.

Conduction

Heat moving through direct contact, usually in solids, as particles bump into each other.

Conductor

A material that lets heat (or electricity) move through it easily, e.g. metal.

Insulator

A material that heat (or electricity) does NOT move through easily, e.g. air, wood, plastic.

Convection

Heat moving through a liquid or gas because warmer, less dense fluid rises while cooler, denser fluid sinks, creating a circulating flow.

Convection current

The circular movement of a liquid or gas caused by convection.

Radiation

Heat that travels as waves and doesn't need anything to travel through, e.g. heat from the Sun.

Heating curve / cooling curve

A graph of temperature over time. Flat parts show a change of state, like melting or boiling, happening. Sloped sections show a change in temperature,.

Specific heat capacity

The energy needed to heat 1 kg of a substance up by 1°C

Latent heat

Latent heat is the amount of heat energy that 1kg of a substance absorbs or releases when it is changing state (and not temperature).

Current

The flow of electric charge (electrons) around a circuit, measured in amperes (A).

Series circuit

A circuit where components are connected in one loop, one after another.

Parallel circuit

A circuit where components are connected on separate branches.

Voltage

A measure of the electrical energy difference between two points in a circuit, measured in volts (V).

Resistance

A measure of how much a component or material opposes the flow of electric current, measured in ohms (Ω).

Power (electrical)

How fast electrical energy is used or transferred, measured in watts (W).