Watt

The watt is the unit of measurement used in the international system of units for the power ( energy expenditure per time period ). It was named after the Scottish scientist and engineer James Watt. As symbols of the capital letter "W" is used.

The watt is a derived unit. It can be made ​​of basic units such as kg, m and s consist of:

History

The unit is named after James Watt, who is known for his improvement of the efficiency of steam engines. It was proposed in 1882 by the British Science Association and recognized in their second congress in 1889 as a unit of power. " Ampere.volt " Compared with the previously customary unit had the new unit a clearer reference to mechanics, so it has been accepted as a replacement for the unit horsepower electric motors. In 1945, the unit was again defined by the Ninth General Conference on Weights and Measures, and included in the International System of Units 1960.

Viewpoints

One watt is equal to the power to

• Per second to spend a mechanical work of one joule to do (), so for example within a second over a distance of one meter, the force of one newton,
• To flow an electric current of one ampere of a voltage to an electric voltage ( ), or
• One gram of water per minute to about 14.3 K (ie 15 ° C within one minute to about 29.3 ° C) to heat up.

Bearing in mind that the different types of benefits, like energy forms do not always directly interconvertible.

Other examples: magnitude (power)

Overview of units of power

Indication of small and large services

Depending on your needs resolutions for units of measurement are used, eg: