GrayA gray (symbol: Gy , is the SI unit of energy for the absorbed dose of radiation. One gray is the absorption of one joule of radiation energy by one kilogram of matter. One gray equals 100 rad, an older unit. It was defined in 1940 by Louis Harold Gray (1, absorbed dose of radiation - Louis Harold GrayLouis Harold Gray ( 10 November 1905 9 July 1965) was a British physicist who worked mainly on the effects of radiation on biological systems, inventing the field of radiobiology as he went. A summary of his work is given below. Amongst many other achieve
HenryThe henry (symbol H) is the SI unit of inductance. If the rate of change of current in a circuit is one ampere per second and the resulting electromotive force is one volt, then the inductance of the circuit is one henry. The henry has dimensions V·A-1·s, inductance – Joseph HenryJoseph Henry ( December 17 1797 May 13 1878) was an American scientist. While building electromagnets, he discovered the electromagnetic phenomenon of self- inductance. He also discovered mutual inductance, independently of Faraday, but Faraday was the fi
HertzHertz is also the name of a car rental company. See The Hertz Corporation''. The hertz (symbol Hz is the SI unit of frequency. It is named in honour of the German physicist Heinrich Rudolf Hertz who made some important contributions to science in the fiel, frequency – Heinrich Rudolf HertzHeinrich Rudolf Hertz ( February 22, 1857 January 1, 1894), was the German physicist for whom the hertz, the SI unit of frequency, is named. In 1888, he was the first to demonstrate the existence of electromagnetic radiation by building apparatus to produ
JouleThe joule (symbol J also called newton metre or coulomb volt is the SI unit of energy and work. The unit is pronounced to rhyme with "tool", and is named in honour of the physicist James Prescott Joule (1818-1889). 1 joule 1 N · 1 m 1 newton · 1 metre 1 k, energy, work, heat – James Prescott JouleJames Prescott Joule ( December 24, 1818 October 11, 1889) was an English physicist, born in Salford, near Manchester. Joule studied the nature of heat, and discovered its relationship to mechanical work (see energy). This led to the theory of conservatio