HOME TheInfoList
 picture info Density The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ (the lower case Greek letter rho), although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume: ${\displaystyle \rho ={\frac {m}{V}}}$ where ρ is the density, m is the mass, and V is the volume [...More Info...]       [...Related Items...] picture info Weighing Scale Weighing scales (or weigh scales or scales) are devices to measure weight. Spring balances or spring scales calculate weight that is the product of mass into gravity (9.807 m/s2--->) on the force on a spring, whereas a balance or pair of scales using a balance beam compares masses by balancing the weight due to the mass of an object against the weight of one or more known masses. Some of them can be calibrated to read in units of force (weight) such as newtons instead of units of mass such as kilograms. The balance or pair of scales using a traditional balance beam to compare masses may read correctly for mass even if moved to a place with a different non-zero gravitational field strength. Also the spring balances that are designed with reading of weight (force) in mind, would read correctly for weight in a different non-zero gravitational field strength. Scales and balances are widely used in commerce, as many products are sold and packaged by mass [...More Info...]       [...Related Items...] picture info Gram The gram (alternative spelling: gramme; SI unit symbol: g) (Latin gramma, from Greek γράμμα, grámma) is a metric system unit of mass. Originally defined as "the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre, and at the temperature of melting ice" (later at 4 °C, the temperature of maximum density of water) [...More Info...]       [...Related Items...] picture info Thermodynamics Thermodynamics is a branch of physics concerned with heat and temperature and their relation to other forms of energy and work. The behavior of these quantities is governed by the four laws of thermodynamics, irrespective of the composition or specific properties of the material or system in question. The laws of thermodynamics are explained in terms of microscopic constituents by statistical mechanics [...More Info...]       [...Related Items...] picture info US Customary Units United States customary units are a system of measurements commonly used in the United States. The United States customary system (USCS or USC) developed from English units which were in use in the British Empire before the U.S. became an independent country. However, the United Kingdom's system of measures was overhauled in 1824 to create the imperial system, changing the definitions of some units. Therefore, while many U.S. units are essentially similar to their Imperial counterparts, there are significant differences between the systems. The majority of U.S. customary units were redefined in terms of the meter and the kilogram with the Mendenhall Order of 1893 and, in practice, for many years before. These definitions were refined by the international yard and pound agreement of 1959. Americans primarily use customary units in commercial activities, as well as for personal and social use [...More Info...]       [...Related Items...] picture info Convection Convection is the heat transfer due to bulk movement of molecules within fluids such as gases and liquids, including molten rock (rheid). Convection takes place through advection, diffusion or both. Thermal image of a just lit Ghillie kettle, note the plume of hot air resulting from the convection current. Convection cannot take place in most solids because neither bulk current flows nor significant diffusion of matter can take place. Diffusion of heat takes place in rigid solids, but that is called heat conduction. Convection, however, can take place in soft solids or mixtures where solid particles can move past each other. Thermal convection can be demonstrated by placing a heat source (e.g [...More Info...]       [...Related Items...] picture info Homogeneous (chemistry) A Homogeneous mixture is a solid, liquid or gaseous mixture that has the same proportions of its components throughout a given sample (or multiple samples of different proportion). Homogeneous mixtures can have a variable composition. Conversly, a heterogeneous mixture does not have uniform in composition, but proportions of its components vary throughout the sample. "Homogeneous" and "heterogeneous" are not absolute terms, but depend on context and size of the sample. In chemistry, a homogeneous suspension of material means that when dividing the volume in half, the same amount of material is suspended in both halves of the substance. However, it might be possible to see the particles under the microscope. An example of a homogeneous mixture is air. In physical chemistry and materials science that refers to substances and mixtures which are in a single phase [...More Info...]       [...Related Items...] picture info Cubic Metre The cubic metre (in British English and international spelling as used by the International Bureau of Weights and Measures) or cubic meter (in American English) is the SI derived unit of volume. Its SI symbol is m3--->. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère, still sometimes used for dry measure (for instance, in reference to wood) [...More Info...]       [...Related Items...] picture info Wreath A wreath is an assortment of flowers, leaves, fruits, twigs, or various materials that is constructed to resemble a ring. In English-speaking countries, wreaths are used typically as household ornaments, mainly as an Advent and Christmas decoration. They are also used in ceremonial events in many cultures around the globe. Wreaths have much history and symbolism associated with them. They are usually made from evergreens and symbolize strength, as evergreens last even throughout the harshest winters [...More Info...]       [...Related Items...] Standard Conditions For Temperature And Pressure Standard conditions for temperature and pressure are standard sets of conditions for experimental measurements to be established to allow comparisons to be made between different sets of data. The most used standards are those of the International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and Technology (NIST), although these are not universally accepted standards [...More Info...]       [...Related Items...] picture info Hydrometer A hydrometer or areometer is an instrument that measures the specific gravity (relative density) of liquids—the ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass, and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright. The liquid to test is poured into a tall container, often a graduated cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer correlates to specific gravity. Hydrometers usually contain a scale inside the stem, so that the person using it can read specific gravity [...More Info...]       [...Related Items...] picture info Packaging Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages. Packaging can be described as a coordinated system of preparing goods for transport, warehousing, logistics, sale, and end use [...More Info...]       [...Related Items...] picture info Goldsmith A goldsmith is a metalworker who specializes in working with gold and other precious metals. Historically, goldsmiths also have made silverware, platters, goblets, decorative and serviceable utensils, ceremonial or religious items, and rarely using Kintsugi, but the rising prices of precious metals have curtailed the making of such items to a large degree. Goldsmiths must be skilled in forming metal through filing, soldering, sawing, forging, casting, and polishing metal. The trade has very often included jewellery-making skills, as well as the very similar skills of the silversmith. Traditionally, these skills had been passed along through apprenticeships, however, more recently jewellery arts schools specializing solely in teaching goldsmithing and a multitude of skills falling under the jewellery arts umbrella are available [...More Info...]       [...Related Items...] picture info Close-packing Of Equal Spheres In geometry, close-packing of equal spheres is a dense arrangement of congruent spheres in an infinite, regular arrangement (or lattice). Carl Friedrich Gauss proved that the highest average density – that is, the greatest fraction of space occupied by spheres – that can be achieved by a lattice packing is ${\displaystyle {\frac {\pi }{3{\sqrt {2}}}}\simeq 0.74048.}$ The same packing density can also be achieved by alternate stackings of the same close-packed planes of spheres, including structures that are aperiodic in the stacking direction [...More Info...]       [...Related Items...] picture info Compressibility In thermodynamics and fluid mechanics, compressibility (also known as the coefficient of compressibility or isothermal compressibility) is a measure of the relative volume change of a fluid or solid as a response to a pressure (or mean stress) change. [...More Info...]       [...Related Items...]