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Beaufort scale

(Encyclopedia)Beaufort scale, a scale of wind velocity devised (c.1805) by Admiral Sir Francis Beaufort of the British navy. An adaptation of Beaufort's scale is used by the U.S. National Weather Service; it employ...

harmonic motion

(Encyclopedia)CE5 Harmonic motion is exhibited by a weight vibrating on the end of a spring. In A, the displacement of the object from its equilibrium position and the acceleration of the object are at a maximum...

river

(Encyclopedia)river, stream of water larger than a brook or creek. Land surfaces are never perfectly flat, and as a result the runoff after precipitation tends to flow downward by the shortest and steepest course i...

Lorentz contraction

(Encyclopedia)Lorentz contraction lôrˈĕnts [key], in physics, contraction or foreshortening of a moving body in the direction of its motion, proposed by H. A. Lorentz on theoretical grounds and based on an earli...

Marvin, Charles Frederick

(Encyclopedia)Marvin, Charles Frederick, 1858–1943, American meteorologist, b. Putnam (now part of Zanesville), Ohio, grad. Ohio State Univ., 1883. He entered (1884) the U.S. Signal Service, predecessor of the We...

Cornu, Marie Alfred

(Encyclopedia)Cornu, Marie Alfred märēˈ älfrĕdˈ kôrnüˈ [key], 1841–1902, French physicist. From 1867 he was professor at the École polytechnique, Paris. He measured the velocity of light and made import...

pitot static system

(Encyclopedia)pitot static system pētōˈ [key], device for measuring the rate at which a fluid flows. Among the principal applications of the device are an airspeed indicator for aircraft and a distance and speed...

solar wind

(Encyclopedia)solar wind, stream of ionized hydrogen—protons and electrons—with an 8% component of helium ions and trace amounts of heavier ions that radiates outward from the sun at high speeds. The continuous...

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...

Mach number

(Encyclopedia)Mach number mäk [key] [for E. Mach], ratio between the speed of an object and the speed of sound in the medium in which the object is traveling. An airplane that has the velocity of Mach 3.0 is trave...

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