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specific gravity

(Encyclopedia)specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the t...

specific heat

(Encyclopedia)specific heat, ratio of the heat capacity of a substance to the heat capacity of a reference substance, usually water. Heat capacity is the amount of heat needed to change the temperature of a unit ma...

hydrometer

(Encyclopedia)hydrometer hīdrŏmˈətər [key], device used to determine directly the specific gravity of a liquid. It usually consists of a thin glass tube closed at both ends, with one end enlarged into a bulb t...

density

(Encyclopedia)density, ratio of the mass of a substance to its volume, expressed, for example, in units of grams per cubic centimeter or pounds per cubic foot. The density of a pure substance varies little from sam...

gravity

(Encyclopedia)gravity: see gravitation.

gravitation

(Encyclopedia)gravitation, the attractive force existing between any two particles of matter. The term gravitygravity is commonly used synonymously with gravitation, but in correct usage a definite distinction is...

Archimedes' principle

(Encyclopedia)Archimedes' principle, principle that states that a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid. The principle applies to both floating and submerged bo...

weight

(Encyclopedia)weight, measure of the force of gravity on a body (see gravitation). Since the weights of different bodies at the same location are proportional to their masses, weight is often used as a measure of m...

Delaware and Hudson Canal

(Encyclopedia)Delaware and Hudson Canal dĕlˈəwâr, –wər [key], former waterway, 108 mi (174 km) long, between Honesdale, Pa., and Eddyville, N.Y. (now in Kingston), linking the Delaware and Hudson rivers; bui...

pitchblende

(Encyclopedia)pitchblende pĭchˈblĕndˌ [key], dark, lustrous, heavy mineral, a source of radium and uranium. Largely natural uranium oxides, triuranium octaoxide (U3O8) and uranium dioxide (UO2), it usually cont...
 

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