electrical appliances Flashcards
useful and wasted energy from electric heater
useful- heat
wasted- light
useful and wasted energy from toaster
useful- heating bread
waste- energy heating the toaster
useful and wasted energy from hairdryer
useful- kinetic and hear
waste- sound, heating hairdryer
what affects the rate of how fast an appliance transfers energy
the more powerful an appliance the faster it transfers energy
how to calculate power
power= energy/ time
what is 1 Watt equal to in Joules
1J/s (one joule per second)
how to work out power effientcy
same as energy
what does the energy supplies to an appliance depend on
- how long it is used for
2. the power supplies to it
equation for how much energy is supplied to something
energy= power X time
what does the electricity meter in your home measure
how much electrical energy your family uses (kWh)
equation to work out total cost
total cost= number of kWh used X cost per kWh
what does cost effective mean
how much something gives value for money
what to consider when considering cost effectiveness
- capital costs- buying/ installing
- running costs- fuel/ maintenance
- environmental costs- tax/ disposal
- other- interest on loans
useful and wasted energy from lightbulb
useful- light
wasted- heat
how easily can electrical appliances transfer electrical energy into useful energy
electrical appliances can transfer electrical energy into useful energy at the flick of a switch