Mathematics and Society - OS X Lion Server

C£OJSARYbarometer. An instrument for measuringthe pressure of the atmosphere.a. aneroid barometer. A barometermade from a partly evacuated, airtightmetal box which is hooked to ascale.b. mereury barometer. A barometermade from a mercury column supportedabove a bowl of mercury.eenter of eurvature. A sphericalmirror is thought of as part of asphere. The center of the sphere isthe center of curvature of the mirror.eenter of gravity. The points whereall mass or weight of a body seemsto be located. Also called balancepoint.eoneave mirror. A curved mirror suchthat two rays from a light sourcewill intersect. The reflecting surfaceof the mirror appears to beII caved in. tIfoeal length. One-half the radius ofa spherical mirror.foeal point. When parallel light raysfallon a curved mirror, the pointwhere the reflected rays intersect isthe focal point.fulerum.Support for a lever.fulcrumgravity. The mutual force of attractionbetween bodies. A measure of thegravity is weight.half-life. The length of time requiredfor half of the radioactive particlesin a substance to decay.image length. The measure of the distancebetween a mirror or lens and theimage formed by the mirror or lens.ineidenee, angle of (i). The anglebetween the incident ray and the perpendicularat the point of incidence.I,,,i: PERPEJJDICULARindex of refraetion. The ratio of thespeed of light in a vacuum to thespeed of light in any transparentmateriaLlever. A rigid bar which can rotateover a fulcrum.light year. The distance light cantravel in one year, ~ 9.5 x 10 12 km.mass. A measure of the amount of matterin a body. In the metric system thisis expressed in grams or kilograms.objeet length. The measure of the distancebetween a mirror or lens and theobject in front of the mirror or lens.pendulum. A suspended mass which isfree to swing back and forth.foree. A push or pull tending to produceor prevent motion. In the metricsystem the unit is newtons or dynes.pressure, atmospherie. The force perunit area caused by air. In the metricsystem this is measured in newtons/cm 2or dynes/cm 2 • In the English systemthis is measured in pounds/i~2.369bar-pre