The equation for power is:
In 1783, James Watt, via a number of experiments, determined that one average “brewery horse”, hooked to a turn style, could lift 33,000 foot-pounds per minute. The unit of one horsepower (HP), thereafter, came to be defined as the amount of lifting work "work", measured in foot-pounds per minute, an average horse could do per hour. Watt used this new unit as way to classify how much various types of Watt engines could sell for in the market place.
The unit of power is the watt or joules per second (J/s), as shown below:
- Newton (unit) | Force | kg⋅m/s²
- Joule (unit) | Energy | N⋅m | kg⋅m²/s²
- Watt (unit) | Power | J/s | kg⋅m²/s³
In c.1900, SI unit "watt" was defined as equivalent to a unit of electrical power equal to one ampere under a pressure of one volt; or to 1/746 horsepower.
- Power – Hmolpedia 2020.