Energy Changes in a System (AQA GCSE Physics): Flashcards

Heat moving from a warm place to a cooler place

Faster heat transfer

Slower heat transfer

How good a material is at letting heat pass through it

Good conductor of heat (e.g., metals)

Poor conductor of heat (e.g., plastic, wood)

How good a device is at transferring energy into useful forms

Less than 100% (no machine is 100% efficient)

$\frac{\text{useful energy}}{\text{total energy}} \times 100\%$

No units (given as a percentage)

Reducing friction

Air resistance