Power (Physics)
Definition
The rate at which work is done or energy is transferred, measured in watts (W). Power = Work ÷ Time.
Why is Power (Physics) Important?
Power (Physics) is a core physics concept that describes the fundamental behavior of matter and energy. Understanding this principle enables engineers, students, and scientists to design better systems, solve real-world problems, and predict physical phenomena with precision.
Our physics calculators make it easy to compute values related to this concept, bridging the gap between theoretical understanding and practical application in engineering, education, and research.
What is Power?
Power is the rate at which work is done or energy is transferred, measured in watts (W). One watt equals one joule per second. Power describes HOW FAST energy is used, not how MUCH energy is used.
Power Formulas
| Formula | Use |
|---|---|
| P = W / t | Power = work ÷ time |
| P = F × v | Power = force × velocity |
| P = ΔE / t | Power = energy change ÷ time |
| P = V × I | Electrical power = voltage × current |
Power Units
| Unit | Equivalent | Context |
|---|---|---|
| 1 Watt (W) | 1 J/s | SI standard |
| 1 Kilowatt (kW) | 1,000 W | Appliances, EV motors |
| 1 Megawatt (MW) | 1,000,000 W | Power plants |
| 1 Horsepower (HP) | 745.7 W | Engines, motors |
Power in Daily Life
| Device / Activity | Power |
|---|---|
| LED light bulb | 8–15 W |
| Laptop computer | 30–65 W |
| Human body (resting) | ~80 W |
| Microwave oven | 1,000–1,200 W |
| Hair dryer | 1,500–1,875 W |
| EV motor (Tesla Model 3) | ~211 kW peak |
| Commercial jet engine | ~80,000 kW per engine |
| Nuclear power plant | ~1,000 MW (1 GW) |