The Northrop B-2 Spirit,also known as the Stealth Bomber,is an American heavy strategic bomber,featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses. A subsonic flying wing with a crew of two,the plane was designed by Northrop as the prime contractor,with Boeing,Hughes,and Vought as principal subcontractors,and was produced from 1987 to 2000. The bomber can drop conventional and thermonuclear weapons,such as up to eighty 500-pound class (230 kg) Mk 82 JDAM GPS-guided bombs,or sixteen 2,400-pound (1,100 kg) B83 nuclear bombs. The B-2 is the only acknowledged in-service aircraft that can carry large air-to-surface standoff weapons in a stealth configuration.
In mathematics,the Fibonacci sequence is a sequence in which each number is the sum of the two preceding ones. Numbers that are part of the Fibonacci sequence are known as Fibonacci numbers,commonly denoted Fn . The sequence commonly starts from 0 and 1,although some authors start the sequence from 1 and 1 or sometimes from 1 and 2. Starting from 0 and 1,the sequence begins
The high jump is a track and field event in which competitors must jump unaided over a horizontal bar placed at measured heights without dislodging it. In its modern,most-practiced format,a bar is placed between two standards with a crash mat for landing. Since ancient times,competitors have successively improved their technique until developing the universally preferred Fosbury Flop,in which athletes run towards the bar and leap head first with their back to the bar.
In probability theory and statistics,a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is The parameter is the mean or expectation of the distribution,while the parameter is the variance. The standard deviation of the distribution is . A random variable with a Gaussian distribution is said to be normally distributed,and is called a normal deviate.
The number π is a mathematical constant that is the ratio of a circle's circumference to its diameter,approximately equal to 3.14159. The number π appears in many formulae across mathematics and physics. It is an irrational number,meaning that it cannot be expressed exactly as a ratio of two integers,although fractions such as are commonly used to approximate it. Consequently,its decimal representation never ends,nor enters a permanently repeating pattern. It is a transcendental number,meaning that it cannot be a solution of an equation involving only finite sums,products,powers,and integers. The transcendence of π implies that it is impossible to solve the ancient challenge of squaring the circle with a compass and straightedge. The decimal digits of π appear to be randomly distributed,but no proof of this conjecture has been found.
A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example,5 is prime because the only ways of writing it as a product,1 ×5 or 5 ×1,involve 5 itself. However,4 is composite because it is a product (2 × 2) in which both numbers are smaller than 4. Primes are central in number theory because of the fundamental theorem of arithmetic:every natural number greater than 1 is either a prime itself or can be factorized as a product of primes that is unique up to their order.
Quantum mechanics is a fundamental theory that describes the behavior of nature at and below the scale of atoms. It is the foundation of all quantum physics,which includes quantum chemistry,quantum field theory,quantum technology,and quantum information science.
In statistics,the standard deviation is a measure of the amount of variation of the values of a variable about its mean. A low standard deviation indicates that the values tend to be close to the mean of the set,while a high standard deviation indicates that the values are spread out over a wider range. The standard deviation is commonly used in the determination of what constitutes an outlier and what does not.
A triangle is a polygon with three corners and three sides,one of the basic shapes in geometry. The corners,also called vertices,are zero-dimensional points while the sides connecting them,also called edges,are one-dimensional line segments. A triangle has three internal angles,each one bounded by a pair of adjacent edges;the sum of angles of a triangle always equals a straight angle. The triangle is a plane figure and its interior is a planar region. Sometimes an arbitrary edge is chosen to be the base,in which case the opposite vertex is called the apex;the shortest segment between base and apex is the height. The area of a triangle equals one-half the product of height and base length.
2 (two) is a number,numeral and digit. It is the natural number following 1 and preceding 3. It is the smallest and the only even prime number.
4 (four) is a number,numeral and digit. It is the natural number following 3 and preceding 5. It is a square number,the smallest semiprime and composite number,and is considered unlucky in many East Asian cultures.
ISO 3166-1 alpha-2 codes are two-letter country codes defined in ISO 3166-1,part of the ISO 3166 standard published by the International Organization for Standardization (ISO),to represent countries,dependent territories,and special areas of geographical interest. They are the most widely used of the country codes published by ISO,and are used most prominently for the Internet's country code top-level domains. They are also used as country identifiers extending the postal code when appropriate within the international postal system for paper mail,and have replaced the previous one consisting one-letter codes. They were first included as part of the ISO 3166 standard in its first edition in 1974.
The United States men's national soccer team (USMNT) represents the United States in men's international soccer competitions. The team is governed by the United States Soccer Federation,which is a member of FIFA and CONCACAF.
Saina Nehwal is an Indian professional badminton player. A former world no. 1,she has won 24 international titles,which includes ten Superseries titles. Although she reached the world's 2nd in 2009,it was only in 2015 that she was able to attain the world no. 1 ranking,thereby becoming the only female player from India and thereafter the second Indian player –after Prakash Padukone –to achieve this feat. She has represented India three times in the Olympics,winning a bronze medal in her second appearance at London 2012.
The PlayStation 2 (PS2) is a home video game console developed and marketed by Sony Computer Entertainment. It was first released in Japan on 4 March 2000,in North America on 26 October 2000,in Europe on 24 November 2000,and in Australia on 30 November 2000. It is the successor to the PlayStation,as well as the second installment in the PlayStation brand of consoles. As a sixth-generation console,it competed with Nintendo's GameCube,Sega's Dreamcast,and Microsoft's Xbox. It is the best-selling video game console of all time,having sold over 160 million units worldwide,nearly triple the combined sales of its competing consoles.
Romelu Menama Lukaku Bolingoli is a Belgian professional footballer who plays as a striker for Premier League club Chelsea and the Belgium national team.
The Academy Award for Best Actor is an award presented annually by the Academy of Motion Picture Arts and Sciences (AMPAS). It has been awarded since the 1st Academy Awards to an actor who has delivered an outstanding performance in a leading role in a film released that year. The award is traditionally presented by the previous year's Best Actress winner.
The version history of the Android mobile operating system began with the public release of its first beta on November 5,2007. The first commercial version,Android 1.0,was released on September 23,2008.
The operating system is developed by Google on a yearly cadence since at least 2011. New major releases are announced at Google I/O in May while still in beta testing with the stable version usually released to the public between August and October.
Deadpool 2 is a 2018 American superhero film based on the Marvel Comics character Deadpool. It is the sequel to Deadpool (2016) and the eleventh installment in the X-Men film series. The film was directed by David Leitch and written by Rhett Reese,Paul Wernick,and Ryan Reynolds,who stars in the title role alongside Josh Brolin,Morena Baccarin,Julian Dennison,Zazie Beetz,T.J. Miller,Brianna Hildebrand,and Jack Kesy. In the film,Deadpool forms the X-Force to protect a young mutant from the time-traveling soldier Cable.
