Skip to main content Skip to Search Box

Definition: power from Philip's Encyclopedia

In physics, rate of doing work or of producing or consuming energy. It is a measure of the output of an engine or other power source. The Scottish engineer James Watt was the first to measure power; he used the unit called horsepower. The modern unit of power is the watt, named after him.

Summary Article: power, in physics
from The Columbia Encyclopedia

in physics, time rate of doing work or of producing or expending energy. The unit of power based on the English units of measurement is the horsepower, devised for describing mechanical power by James Watt, who estimated that a horse can do 550 ft-lb of work per sec; a foot-pound is the work done when a weight (force) of 1 lb is moved through a distance of 1 ft. The unit of power in the metric system is the watt, named in honor of James Watt and equal to 1 joule per sec; the watt is used for measuring electric power in most countries, even those still using English units for other quantities. In common usage, the terms power and energy have become synonymous; for example, electrical energy is usually referred to as electric power (see power, electric). See also energy, sources of.

The Columbia Encyclopedia, © Columbia University Press 2018

Related Articles

Full text Article power
Academic Press Dictionary of Science and Technology

The ability to do or act; being able to cause some change or activity; specific uses include: Engineering : 1. Any type of physical...

Full text Article power
The Macmillan Encyclopedia

The rate at which a body or system does work. It is measured in watts or horsepower. If a body of mass m is raised a height h in the...

Full text Article power
The Penguin Dictionary of Physics

1. Symbol: P . The rate at which energy is expended or work is done. It is measured in WATTS . The power P developed in a...

See more from Credo