Power
Also: rate of energy transfer
How quickly energy is transferred or converted.
Power is the time derivative of energy; electrical DC power is VI and mechanical rotational power is torque times angular speed.
- Units
- watt (W = J/s)
- Formula
P = dE/dt; P = VI; P = τω
Example A 5 V device drawing 0.4 A consumes 2 W electrically.
Common misconception Power is a rate, not stored energy or battery capacity.