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centripetal force and centrifugal force

(Encyclopedia)CE5 Centripetal and centrifugal forces: When a ball is swung in a circle at the end of a string, centripetal and centrifugal forces act as shown above. centripetal force and centrifugal force, act...

Gay-Lussac, Joseph Louis

(Encyclopedia)Gay-Lussac, Joseph Louis zhôzĕfˈ lwē gā-lüsäkˈ [key], 1778–1850, French chemist and physicist. He was professor in Paris at the Sorbonne, at the Polytechnic School, and at the Jardin des Pla...

photon

(Encyclopedia)photon fōˈtŏn [key], the particle composing light and other forms of electromagnetic radiation, sometimes called light quantum. The photon has no charge and no mass. About the beginning of the 20th...

Lloyd, David

(Encyclopedia)Lloyd, David, c.1656–1731, political leader in colonial Pennsylvania, b. Wales. Having been commissioned attorney general of Pennsylvania by William Penn, Lloyd arrived in Philadelphia in 1686. He l...

servomechanism

(Encyclopedia)servomechanism, automatic device for the control of a large power output by means of a small power input or for maintaining correct operating conditions in a mechanism. It is a type of feedback contro...

sampler

(Encyclopedia)sampler, sample piece of needlework or embroidery, of silk, cotton, or worsted, for the preservation of some pattern or as an example of the ability of a child or a beginner. In museums and private co...

Beernaert, Auguste

(Encyclopedia)Beernaert, Auguste ōgüstˈ bârnärtˈ, bârˈnärt [key], 1829–1912, Belgian statesman. A member of the liberal wing of the Catholic party, he served in several cabinets and was prime minister fr...

Neopaganism

(Encyclopedia)Neopaganism, polytheistic religious movement, practiced in small groups by partisans of pre-Christian religious traditions such as Egyptian, Greek, Norse, and Celtic. Neopagans fall into two broad cat...

organum

(Encyclopedia)organum ôrˈgənəm [key], in music, compositional technique, developed in Europe during the 10th cent., in which each note of Gregorian chant melody was doubled by another note. In the earliest exam...

mass, in physics

(Encyclopedia)mass, in physics, the quantity of matter in a body regardless of its volume or of any forces acting on it. The term should not be confused with weight, which is the measure of the force of gravity (se...