Energy Changes in a System (AQA GCSE Physics Combined Science): Flashcards
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Practise the cards
14 cards from this deck
What does efficiency measure
What does efficiency measure
How much useful energy out vs total energy in
Efficiency formula
Efficiency formula
Units of efficiency
Units of efficiency
No units (it's a percentage)
Maximum efficiency any machine can achieve
Maximum efficiency any machine can achieve
Less than 100%
3 factors affecting thermal energy transfer rate
3 factors affecting thermal energy transfer rate
Temp difference, wall thickness, thermal conductivity
Effect of bigger temp difference on energy transfer
Effect of bigger temp difference on energy transfer
Faster energy transfer
Effect of thicker walls on energy transfer
Effect of thicker walls on energy transfer
Slower energy transfer
Thermal conductivity definition
Thermal conductivity definition
How well a material lets thermal energy pass through it
High thermal conductivity means
High thermal conductivity means
Good conductor of energy (like metals)
Low thermal conductivity means
Low thermal conductivity means
Poor conductor, good insulator (like wood)
Lubrication improves efficiency by reducing
Lubrication improves efficiency by reducing
Friction in moving parts
Low resistance wires reduce
Low resistance wires reduce
Energy lost as heat in electrical circuits
Streamlined shapes reduce
Streamlined shapes reduce
Air resistance for moving objects
What most wasted energy becomes
What most wasted energy becomes
Heat