In everyday life, power is often measured in kilowatts (kW) because watts are too small for most appliances. In engineering and power generation, megawatts (MW) and gigawatts (GW) are used.
| Unit | Symbol | Value |
|---|---|---|
| Watt | W | 1 J/s |
| Kilowatt | kW | 1,000 W |
| Megawatt | MW | 1,000,000 W |
| Gigawatt | GW | 1,000,000,000 W |
Typical power values:
- Phone charger: ~5 W
- LED bulb: ~10 W
- Laptop: ~50 W
- Human resting: ~80 W
- Human sprinting: ~2,000 W (2 kW)
- Kettle: ~3,000 W (3 kW)
- Car engine: ~75,000 W (75 kW)
- Power station: ~1,000,000,000 W (1 GW)
This deep dive covers Power Units and Typical Values within Power for GCSE Physics. Revise Power in Energy for GCSE Physics with 14 exam-style questions and 25 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 3 of 12 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Power
Which of the following is the correct definition of power?
A microwave oven transfers 54,000 J of energy. It has a power rating of 900 W. Calculate how long the microwave was switched on. Use the equation: power = energy transferred / time Give your answer in seconds (s).