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.
🔌 Power Units and Typical Values
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)
Practice questions for Power
Which of the following is the correct definition of power?
State what is meant by the term 'power' in physics and state its unit.
Quick recall flashcards
What is power?
Power is the rate at which energy is transferred or work is done. It is measured in watts (W).
What is mechanical power?
Mechanical power is the rate at which mechanical work is done or mechanical energy is transferred, calculated using P = W/t.