density


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms, Wikipedia.
Related to density: relative density, specific gravity, Population density

density,

ratio of the massmass,
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 (see gravitation) acting on a body.
..... Click the link for more information.
 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 sample to sample and is often considered a characteristic property of the substance. Most substances undergo expansion when heated and therefore have lower densities at higher temperatures. Many substances, especially gases, can be compressed into a smaller volume by increasing the pressure acting on them. For these reasons, the temperature and pressure at which the density of a substance is measured are usually specified. The density of a gas is often converted mathematically to what it would be at a standard temperature and pressure (see STP). Water is unusual in that it expands, and thus decreases in density, as it is cooled below 3.98°C; (its temperature of maximum density). Density often is taken as an indication of how "heavy" a substance is. Iron is denser than cork, since a given volume of iron is more massive (and weighs more) than the same volume of cork. It is often said that iron is "heavier" than cork, although a large volume of cork obviously can be more massive and thus be heavier (i.e., weigh more) than a small volume of iron. See specific gravityspecific 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 two substances.
..... Click the link for more information.
.

Density

The mass per unit volume of a material. The term is applicable to mixtures and pure substances and to matter in the solid, liquid, gaseous, or plasma state. Density of all matter depends on temperature; the density of a mixture may depend on its composition, and the density of a gas on its pressure. Common units of density are grams per cubic centimeter, and slugs or pounds per cubic foot. The specific gravity of a material is defined as the ratio of its density to the density of some standard material, such as water at a specified temperature, for example, 60°F (15.6°C), or, for gases the basis may be air at standard temperature and pressure. Another related concept is weight density, which is defined as the weight of a unit volume of the material. See Mass, Weight

density

1. Symbol: ρ. The mass per unit volume of a body or material. The mean density of a celestial body is its total mass divided by its total volume. A wide variation in densities is found in the Universe, ranging from about 10–20 kg m–3 for interstellar gas to over 1017 kg m–3 for neutron stars. The mean density of matter in the Universe is of the order of 10–27 kg m–3.
2. The number of electrons, ions, or other particles per unit volume.

Density

A planning or zoning unit of measurement of the ratio between buildings per acre, or occupants per gross square foot of floor area, according to the type of zoning for that particular area under consideration, such as commercial residential, rural, and the like.

Density

 

in textiles, the content of fibrous material per unit volume. The density of a weave determines the strength and appearance of the fabric. It is usually expressed by the number of warp threads per unit of width and the number of filling threads per unit of length—that is, the ratio of absolute density along warp and filling. When the linear density (fineness) of the threads varies, a ratio of relative density is used, expressed by a filling coefficient—linear, surface, or volume—representing the relationship of the linear measurements of surface or volume to the overall width, length, surface, or volume of a unit of material. The relative density is determined basically by the type of fiber interlacing used in the weave. For a weave of normal density, about 40 or 50 percent of the volume of a fabric consists of fibrous material.

density

[′den· səd·ē]
(materials)
Closeness of texture or consistency.
(mathematics)
For an increasing sequence of integers, the greatest lower bound of the quantity F (n)/ n, where F (n) is the number of integers in the sequence (other than zero) equal to or less than n.
(mechanics)
The mass of a given substance per unit volume.
(optics)
The degree of opacity of a translucent material.
The common logarithm of opacity.
(physics)
The total amount of a quantity, such as energy, per unit of space.

density

The degree of aggregation; the quantity of any entity distributed over an area per unit of areal measure, e.g., persons per acre, families per acre, or dwelling units per square mile.

density

1. a measure of the compactness of a substance, expressed as its mass per unit volume. It is measured in kilograms per cubic metre or pounds per cubic foot.
2. a measure of a physical quantity per unit of length, area, or volume
References in classic literature ?
Even the Susquehanna was then hid by the height and density of the forest.
There was something about the luxury of the Welland house and the density of the Welland atmosphere, so charged with minute observances and exactions, that always stole into his system like a narcotic.
The air was so thick with the darkness of the day and the density of the fall that we could see but a very little way in any direction.
At the height of six thousand feet, the density of the atmosphere has already greatly diminished; sound is conveyed with difficulty, and the voice is not so easily heard.
Quietly and steadily there rose up behind the whole aspect of life that soft edge of fire which gave its red tint to the atmosphere and crowded the scene with shadows so deep and dark that one could fancy pushing farther into their density and still farther, exploring indefinitely.
The blackness seemed suddenly to increase in density, and they stumbled up the beach, feeling their way to the gate.
Imagine, further, this sand to be invisible, impalpable, yet to retain all the weight and density of sand.
Near the horizon the sun was smouldering dimly, almost obscured by formless mists and vapors, which gave an impression of mass and density without outline or tangibility.
The moon, gentlemen, has been carefully studied," continued Barbicane; "her mass, density, and weight; her constitution, motions, distance, as well as her place in the solar system, have all been exactly determined.
If we must compare the eye to an optical instrument, we ought in imagination to take a thick layer of transparent tissue, with a nerve sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different densities and thicknesses, placed at different distances from each other, and with the surfaces of each layer slowly changing in form.
They feared this apparition fully as much as they did Numa, yet they would gladly have slain the thing could they quickly enough have gathered together their wits; but fear and superstition and a natural mental density held them paralyzed while the ape-man stooped and gathered up the lion skin.
Suddenly upon the beach he saw what at first he imagined must be an optical illusion - a long shaft of light, invisible in itself except that it seemed to slightly change the density of the mist.