Watt

The watt (symbol: W) is a derived unit of power in the International System of Units (SI). It measures rate of energy conversion. One watt is equivalent to 1 joule (J) of energy per second. In terms of mechanical energy, one watt is the rate at which work is done when an object is moved at a speed of one meter per second against a force of one newton. By the definitions of electric potential (volt) and current (ampere), work is done at a rate of ... more

The watt (symbol: W) is a derived unit of power in the International System of Units (SI). It measures rate of energy conversion. One watt is equivalent to 1 joule (J) of energy per second. In terms of mechanical energy, one watt is the rate at which work is done when an object is moved at a speed of one meter per second against a force of one newton. By the definitions of electric potential (volt) and current (ampere), work is done at a rate of one watt when one ampere flows through a potential difference of one volt. A human climbing a flight of stairs is doing work at a rate of about 200watts. A typical automobile engine produces mechanical energy at a rate of 25000watts (approximately 33.5 horsepower) while cruising. A typical household incandescent light bulb uses electrical energy at a rate of 25 to 100 watts; fluorescent lamps typically consume 5 to 30 watts to produce a similar amount of light. The watt is named after James Watt for his contributions to the development of the... less