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inclined plane

(Encyclopedia)CE5 Inclined plane inclined plane, simple machine, consisting of a sloping surface, whose purpose is to reduce the force that must be applied to raise a load. To raise a body vertically a force mu...

force

(Encyclopedia)force, commonly, a “push” or “pull,” more properly defined in physics as a quantity that changes the motion, size, or shape of a body. Force is a vector quantity, having both magnitude and dir...

pound

(Encyclopedia)pound, abbr. lb, unit of either mass or force in the customary system of English units of measurement. Two different pounds of mass are defined, one in the avoirdupois system of units and one in the T...

airfoil

(Encyclopedia)airfoil, surface designed to develop a desired force by reaction with a fluid, especially air, that is flowing across the surface. For example, the fixed wing surfaces of an airplane produce lift, whi...

neodymium

(Encyclopedia)neodymium nēˌōdĭmˈēəm [key], metallic chemical element; symbol Nd; at. no. 60; at. wt. 144.242; m.p. about 1,021℃; b.p. about 3,068℃; sp. gr. 7.004 at 20℃; valence +3. Neodymium is a lust...

Struve

(Encyclopedia)Struve shtro͞oˈvə [key], family of astronomers. Friedrich Georg Wilhelm von Struve, 1793–1864, was born in Germany but later lived in Russia. While director (1817–39) of Dorpat Observatory he w...

Tz'u Hsi

(Encyclopedia)Tz'u Hsi, Tsu Hsi, Tse Hsi, or Cixi all: tso͝o shē [key], 1834–1908, dowager empress of China (1861–1908) and regent (1861–73, 1874–89, 1898–1908). Her failure to realize the gravity of ...

Ursa Major and Ursa Minor

(Encyclopedia)Ursa Major ûrˈsə [key] and Ursa Minor [Lat.,=the great bear; the little bear], two conspicuous northern constellations. Known to many peoples from ancient times, these constellations have had vario...

symbiosis

(Encyclopedia)symbiosis sĭmbēōˈsĭs [key], the habitual living together of organisms of different species. The term is usually restricted to a dependent relationship that is beneficial to both participants (als...

commensalism

(Encyclopedia)commensalism kəmĕnˈsəlĭzˌəm [key], relationship between members of two different species of organisms in which one individual is usually only slightly benefited, while the other member is not a...