EquationIn mathematics, an equation is a mathematical formula that expresses the equality of two expressions, by connecting them with the equals sign . The word equation and its cognates in other languages may have subtly different meanings; for example, in French an équation is defined as containing one or more variables, while in English, any well-formed formula consisting of two expressions related with an equals sign is an equation. Solving an equation containing variables consists of determining which values of the variables make the equality true.
Lincoln TunnelThe Lincoln Tunnel is an approximately tunnel under the Hudson River, connecting Weehawken, New Jersey, to the west with Midtown Manhattan in New York City to the east. It carries New Jersey Route 495 on the New Jersey side and unsigned New York State Route 495 on the New York side. It was designed by Ole Singstad and named after Abraham Lincoln. The tunnel consists of three vehicular tubes of varying lengths, with two traffic lanes in each tube.
Ocean linerAn ocean liner is a type of passenger ship primarily used for transportation across seas or oceans. Ocean liners may also carry cargo or mail, and may sometimes be used for other purposes (such as for pleasure cruises or as hospital ships). Only one ocean liner remains in service today. The category does not include ferries or other vessels engaged in short-sea trading, nor dedicated cruise ships where the voyage itself, and not transportation, is the primary purpose of the trip.
International Prototype of the KilogramThe International Prototype of the Kilogram (referred to by metrologists as the IPK or Le Grand K; sometimes called the ur-kilogram, or urkilogram, particularly by German-language authors writing in English:30) is an object whose mass was used to define the kilogram from 1889, when it replaced the Kilogramme des Archives, until 2019, when it was replaced by a new definition of the kilogram based entirely on physical constants. During that time, the IPK and its duplicates were used to calibrate all other kilogram mass standards on Earth.
History of the metreThe history of the metre starts with the Scientific Revolution that is considered to have begun with Nicolaus Copernicus's publication of De revolutionibus orbium coelestium in 1543. Increasingly accurate measurements were required, and scientists looked for measures that were universal and could be based on natural phenomena rather than royal decree or physical prototypes. Rather than the various complex systems of subdivision then in use, they also preferred a decimal system to ease their calculations.
SubsidyA subsidy or government incentive is a type of government expenditure targeted towards individuals and households, as well as businesses with the aim of stabilising the economy. It ensures that individuals and households are viable by having access to essential goods and services while giving businesses the opportunity to stay afloat and/or competitive. Subsidies not only promote long term economic stability but also help governments to respond to economic shocks during a recession or in response to unforeseen shocks such as COVID-19.
Standard (metrology)In metrology (the science of measurement), a standard (or etalon) is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures, against which all other measuring devices are compared. Historical standards for length, volume, and mass were defined by many different authorities, which resulted in confusion and inaccuracy of measurements.
Agricultural subsidyAn agricultural subsidy (also called an agricultural incentive) is a government incentive paid to agribusinesses, agricultural organizations and farms to supplement their income, manage the supply of agricultural commodities, and influence the cost and supply of such commodities. Examples of such commodities include: wheat, feed grains (grain used as fodder, such as maize or corn, sorghum, barley and oats), cotton, milk, rice, peanuts, sugar, tobacco, oilseeds such as soybeans and meat products such as beef, pork, and lamb and mutton.
Cruise shipCruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports of call, where passengers may go on tours known as "shore excursions". On "cruises to nowhere" or "nowhere voyages", some cruise ships make two- to three-night round trips without visiting any ports of call. Modern cruise ships tend to have less hull strength, speed, and agility compared to ocean liners.
Mohr's circleMohr's circle is a two-dimensional graphical representation of the transformation law for the Cauchy stress tensor. Mohr's circle is often used in calculations relating to mechanical engineering for materials' strength, geotechnical engineering for strength of soils, and structural engineering for strength of built structures. It is also used for calculating stresses in many planes by reducing them to vertical and horizontal components.
