The density, of a substance is its mass per unit volume. The symbol most often used for density is ρ, although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume:
Fair use is a doctrine in United States law that permits limited use of copyrighted material without having to first acquire permission from the copyright holder. Fair use is one of the limitations to copyright intended to balance the interests of copyright holders with the public interest in the wider distribution and use of creative works by allowing as a defense to copyright infringement claims certain limited uses that might otherwise be considered infringement. Unlike "fair dealing" rights that exist in most countries with a British legal history, the fair use right is a general exception that applies to all different kinds of uses with all types of works and turns on a flexible proportionality test that examines the purpose of the use, the amount used, and the impact on the market of the original work.
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. Formally, a kinetic energy is any term in a system's Lagrangian which includes a derivative with respect to time.
In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. In older works, power is sometimes called activity. Power is a scalar quantity.
The First Amendment to the United States Constitution prevents the government from making laws which regulate an establishment of religion, or that would prohibit the free exercise of religion, or abridge the freedom of speech, the freedom of the press, the freedom of assembly, or the right to petition the government for redress of grievances. It was adopted on December 15, 1791, as one of the ten amendments that constitute the Bill of Rights.
The Fourteenth Amendment to the United States Constitution was adopted on July 9, 1868, as one of the Reconstruction Amendments. Often considered as one of the most consequential amendments, it addresses citizenship rights and equal protection under the law and was proposed in response to issues related to former slaves following the American Civil War. The amendment was bitterly contested, particularly by the states of the defeated Confederacy, which were forced to ratify it in order to regain representation in Congress. The amendment, particularly its first section, is one of the most litigated parts of the Constitution, forming the basis for landmark Supreme Court decisions such as Brown v. Board of Education (1954) regarding racial segregation, Roe v. Wade (1973) regarding abortion, Bush v. Gore (2000) regarding the 2000 presidential election, and Obergefell v. Hodges (2015) regarding same-sex marriage. The amendment limits the actions of all state and local officials, and also those acting on behalf of such officials.
The Supreme Court of the United States (SCOTUS) is the highest court in the federal judiciary of the United States of America. It has ultimate and largely discretionary appellate jurisdiction over all federal and state court cases that involve a point of federal law, and original jurisdiction over a narrow range of cases, specifically "all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party." The Court holds the power of judicial review, the ability to invalidate a statute for violating a provision of the Constitution. It is also able to strike down presidential directives for violating either the Constitution or statutory law. However, it may act only within the context of a case in an area of law over which it has jurisdiction. The Court may decide cases having political overtones but has ruled that it does not have power to decide non-justiciable political questions.
Henry V, also called Henry of Monmouth, was King of England from 1413 until his death in 1422. Despite his relatively short reign, Henry's outstanding military successes in the Hundred Years' War against France made England one of the strongest military powers in Europe. Immortalised in Shakespeare's "Henriad" plays, Henry is known and celebrated as one of the greatest warrior kings of medieval England.
Brown v. Board of Education of Topeka, 347 U.S. 483 (1954), was a landmark decision of the U.S. Supreme Court in which the Court ruled that U.S. state laws establishing racial segregation in public schools are unconstitutional, even if the segregated schools are otherwise equal in quality. The Court's decision partially overruled its 1896 decision Plessy v. Ferguson, declaring that the "separate but equal" notion was unconstitutional for American public schools and educational facilities. It paved the way for integration and was a major victory of the civil rights movement, and a model for many future impact litigation cases.
Roe v. Wade, 410 U.S. 113 (1973), was a landmark decision of the U.S. Supreme Court in which the Court ruled that the Constitution of the United States protects a pregnant woman's liberty to choose to have an abortion without excessive government restriction. It struck down many U.S. federal and state abortion laws, and prompted an ongoing national debate in the United States about whether and to what extent abortion should be legal, who should decide the legality of abortion, what methods the Supreme Court should use in constitutional adjudication, and what the role of religious and moral views in the political sphere should be. Roe v. Wade reshaped American politics, dividing much of the United States into abortion rights and anti-abortion movements, while activating grassroots movements on both sides.
Charles V was Holy Roman Emperor and Archduke of Austria from 1519 to 1556, King of Spain from 1516 to 1556, and Lord of the Netherlands as titular Duke of Burgundy from 1506 to 1555. As he was head of the rising House of Habsburg during the first half of the 16th century, his dominions in Europe included the Holy Roman Empire, extending from Germany to northern Italy with direct rule over the Austrian hereditary lands and the Burgundian Low Countries, and the Kingdom of Spain with its southern Italian possessions of Naples, Sicily, and Sardinia. Furthermore, his reign encompassed both the long-lasting Spanish and the short-lived German colonization of the Americas. The personal union of the European and American territories of Charles V was the first collection of realms labelled "the empire on which the Sun never sets".
The Argentina national football team represents Argentina in men's international football and is administered by the Argentine Football Association, the governing body for football in Argentina. Argentina's home stadium is Estadio Monumental Antonio Vespucio Liberti in Buenos Aires.
V for Vendetta is a 2005 dystopian political superhero action film directed by James McTeigue from a screenplay by the Wachowskis. It is based on the 1988 DC Comics limited series of the same name by Alan Moore and David Lloyd. The film is set in an alternative future where a fascist totalitarian regime has subjugated the United Kingdom. It centres on V, an anarchist and masked freedom fighter who attempts to ignite a revolution through elaborate terrorist acts, and Evey Hammond a young woman caught up in V's mission. Stephen Rea portrays a detective leading a desperate quest to stop V.
In linear algebra, an eigenvector or characteristic vector of a linear transformation is a nonzero vector that changes at most by a scalar factor when that linear transformation is applied to it. The corresponding eigenvalue, often denoted by , is the factor by which the eigenvector is scaled.
Batman v Superman: Dawn of Justice is a 2016 American superhero film based on the DC Comics characters Batman and Superman. It is a follow-up to Man of Steel (2013) and the second installment in the DC Extended Universe (DCEU). The film was directed by Zack Snyder, written by Chris Terrio and David S. Goyer, and features an ensemble cast that includes Ben Affleck, Henry Cavill, Amy Adams, Jesse Eisenberg, Diane Lane, Laurence Fishburne, Jeremy Irons, Holly Hunter, and Gal Gadot. Batman v Superman: Dawn of Justice is the first live-action film to feature Batman and Superman together, as well as the first live-action cinematic portrayal of Wonder Woman. In the film, criminal mastermind Lex Luthor manipulates Batman into a preemptive battle with Superman, with whom Luthor is obsessed.
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is the coronavirus that causes COVID-19, the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a provisional name, 2019 novel coronavirus (2019-nCoV), and has also been called human coronavirus 2019. First identified in the city of Wuhan, Hubei, China, the World Health Organization declared the outbreak a Public Health Emergency of International Concern on 30 January 2020, and a pandemic on 11 March 2020. SARS‑CoV‑2 is a positive-sense single-stranded RNA virus that is contagious in humans. As described by the US National Institutes of Health, it is the successor to SARS-CoV-1, the virus that caused the 2002–2004 SARS outbreak.
The Finals, formerly known as World Group, was the highest level of Davis Cup competition in 2021. It was held on indoor hard courts at three venues in Innsbruck, Austria, Madrid, Spain and Turin, Italy. The 2020 edition was originally scheduled to take place from 23 until 29 November 2020. However, on 26 June 2020, ITF announced that 2020 Finals would take place from 22 until 28 November 2021 due to coronavirus pandemic and be named 2021 Davis Cup Finals. On 18 January 2021, ITF announced that the Finals would be expanded over 11 days, from 25 November to 5 December 2021. The ties were contested in a best-of-three rubbers format and played on one day. There were two singles followed by a doubles.
The Alpha variant, also known as lineage B.1.1.7, is a variant of SARS-CoV-2, the virus that causes COVID-19. One of several variants of concern, the variant is estimated to be 40–80% more transmissible than the wild-type SARS-CoV-2. It was first detected in November 2020 from a sample taken in September in the United Kingdom, and began to spread quickly by mid-December, around the same time as infections surged. This increase is thought to be at least partly because of one or more mutations in the virus' spike protein. The variant is also notable for having more mutations than normally seen.
There are many variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). Some are believed, or have been stated, to be of particular importance due to their potential for increased transmissibility, increased virulence, or reduced effectiveness of vaccines against them. These variants contribute to the continuation of the COVID-19 pandemic.
The Delta variant is a variant of SARS-CoV-2, the virus that causes COVID-19. It was first detected in India in late 2020. The Delta variant was named on 31 May 2021 and had spread to over 179 countries by 22 November 2021. The World Health Organization (WHO) indicated in June 2021 that the Delta variant is becoming the dominant strain globally.
