Power Calculator
Calculate Power, Work, or Time intervals.
In physics, Power is defined as the rate at which work is done. It tells you not just how much energy you used, but how fast you used it. A strong engine and a weak engine might both lift the same heavy weight (same Work), but the strong engine does it faster (more Power).
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Frequently Asked Questions
Power in Physics
1. The Watt
The unit of power is the Watt (W), named after James Watt, the inventor of the steam engine.
1 Watt = 1 Joule per Second.
So, a 100-Watt light bulb consumes 100 Joules of energy every second it is turned on.
2. Horsepower
Before Watts, we used Horsepower (HP) to sell steam engines to farmers. James Watt calculated that a horse could lift 550 pounds by 1 foot in 1 second.
1 HP ≈ 746 Watts.
So a 100 HP car engine can generate about 74,600 Watts of power.
3. Power vs. Energy
Don't confuse them!
Energy (Joules) is the "capacity" to do work (like the size of a fuel tank).
Power (Watts) is the "rate" of using that energy (how fast you burn the fuel).