Zusammenfassung der Ressource
Power
- Definition
- The rate at which energy is transferred,
or the rate at which work is done.
- Note: Energy transfer of 1 joule
per second = 1 watt of power
- Large Powers
- 1kW = 1 000W (103 W) 1MW =
1 000 000 W (106 W)
- Formulas
- Power= energy transferred/time
- Power= work done/time
- Units
- Joules
- Watts
- Seconds
- Examples
- If a 2,000W kettle boils for
100 seconds, how much
energy is used? Energy =
Power x Time 2,000 x 100 =
200,000 Joules
- A PC has a 800W power supply.
How long is it used for if it
transfers 32,000J of energy? Time
= Energy ÷ Power 32,000 ÷ 800 =
40 seconds