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RPM - Racing Per Matchett
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 defines a physical quantity called ''rotation'' (or ''number of revolutions''), dimensionless, whose instantaneous rate of change is called ''rotational frequency'' (or ''rate of rotation''), with units of reciprocal seconds (s−1). A related but distinct quantity for describing rotation is ''angular frequency'' (or ''angular speed'', the magnitude of angular velocity), for which the SI unit is the radian per second (rad/s). Although they have the same dimensions (reciprocal time) and base unit (s−1), the hertz (Hz) and radians per second (rad/s) are special names used to express two different but proportional ISQ quantities: frequency and angular frequency, respectively. The conversions between a frequency and an angular frequency are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachometer
A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a axle, shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes . Essentially the words tachometer and speedometer have identical meaning: a device that measures speed. It is by arbitrary convention that in the automotive world one is used for engine revolutions and the other for vehicle speed. In formal engineering nomenclature, more precise terms are used to distinguish the two. History The first tachometer was described by Bryan Donkin in a paper to the Royal Society of Arts in 1810 for which he was awarded the Gold medal of the society. This consisted of a bowl of mercury constructed in such a way that centrifugal force caused the level in a central tube to fall when it rotated and brought down the level in a narrower t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engine
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power generation), heat energy (e.g. geothermal), chemical energy, electric potential and nuclear energy (from nuclear fission or nuclear fusion). Many of these processes generate heat as an intermediate energy form; thus heat engines have special importance. Some natural processes, such as atmospheric convection cells convert environmental heat into motion (e.g. in the form of rising air currents). Mechanical energy is of particular importance in transportation, but also plays a role in many industrial processes such as cutting, grinding, crushing, and mixing. Mechanical heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a mechanical heat engine in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automobile
A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, people rather than cargo. There are around one billion cars in use worldwide. The French inventor Nicolas-Joseph Cugnot built the first steam-powered road vehicle in 1769, while the Swiss inventor François Isaac de Rivaz designed and constructed the first internal combustion-powered automobile in 1808. The modern car—a practical, marketable automobile for everyday use—was invented in 1886, when the German inventor Carl Benz patented his Benz Patent-Motorwagen. Commercial cars became widely available during the 20th century. The 1901 Oldsmobile Curved Dash and the 1908 Ford Model T, both American cars, are widely considered the first mass-produced and mass-affordable cars, respectively. Cars were rapidly adopted in the US, where they replac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternator
An alternator (or synchronous generator) is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.Gordon R. Selmon, ''Magnetoelectric Devices'', John Wiley and Sons, 1966 no ISBN pp. 391-393 Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually, the term refers to small rotating machines driven by automotive and other internal combustion engines. An alternator that uses a permanent magnet for its magnetic field is called a magneto. Alternators in power stations driven by steam turbines are called turbo-alternators. Large 50 or 60 Hz three-phase alternators in power plants generate most of the world's electric power, which is distributed by electric power grids. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WFAN (AM)
WFAN (660 AM) is a commercial radio station licensed to New York, New York, with a sports radio format, branded "Sports Radio 66 AM and 101.9 FM" or "The Fan". Owned by Audacy, Inc., the station serves the New York metropolitan area, while its 50,000-watt clear channel signal can be heard at night throughout much of the eastern United States and Canada. WFAN's studios are located in the Hudson Square neighborhood of lower Manhattan and its transmitter is located on High Island in the Bronx. The current WFAN, and its sports format, is the second New York City station with that call sign and programming. The original WFAN was launched on July 1, 1987, on , as the world's first radio station to adopt the sports radio format around-the-clock. The WFAN call letters and sports format were moved to the former WNBC at 660 kHz on October 7, 1988. WNBC's history dated to 1922, when it began operation as WEAF, licensed to Western Electric. Purchased by the Radio Corporation of Amer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breaking Ball
In baseball, a breaking ball is a pitch that does not travel straight as it approaches the batter; it will have sideways or downward motion on it, sometimes both (see slider). A breaking ball is not a specific pitch by that name, but is any pitch that "breaks", such as a curveball, slider, or screwball. A pitcher who primarily uses breaking ball pitches is often referred to as a '' junkballer''. A breaking ball is more difficult than a straight pitch for a catcher to receive as breaking pitches sometimes hit the ground (whether intentionally, or not) before making it to the plate. A curveball moves down and to the left for a right handed pitcher. For a left hand pitcher, it moves down and to the right. And blocking a breaking ball requires thought and preparation by the catcher. The pitcher then, must have confidence in the catcher, and the catcher in himself, to block any ball in the dirt; if there are runners on base, they will likely advance if the ball gets away from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Major League Baseball
Major League Baseball (MLB) is a professional baseball league composed of 30 teams, divided equally between the National League (baseball), National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. MLB is one of the major professional sports leagues in the United States and Canada and is considered the premier professional baseball league in the world. Each team plays 162 games per season, with Opening Day traditionally held during the first week of April. Six teams in each league then advance to a four-round Major League Baseball postseason, postseason tournament in October, culminating in the World Series, a best-of-seven championship series between the two league champions first played in 1903. MLB is headquartered in Midtown Manhattan. Formed in 1876 and 1901, respectively, the NL and AL cemented their cooperation with the National Agreement in 1903, making MLB the oldest major professional sports league in the world. They remained le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baseball
Baseball is a bat-and-ball games, bat-and-ball sport played between two team sport, teams of nine players each, taking turns batting (baseball), batting and Fielding (baseball), fielding. The game occurs over the course of several Pitch (baseball), plays, with each play beginning when a player on the fielding team (baseball), fielding team, called the pitcher, throws a Baseball (ball), ball that a player on the batting team (baseball), batting team, called the Batter (baseball), batter, tries to hit with a baseball bat, bat. The objective of the offensive team (batting team) is to hit the ball into the field of play, away from the other team's players, allowing its players to run the Base (baseball), bases, having them advance counter-clockwise around four bases to score what are called "Run (baseball), runs". The objective of the defensive team (referred to as the fielding team) is to prevent batters from becoming Base running, runners, and to prevent runners base running ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washing Machine
A washing machine (laundry machine, clothes washer, washer, or simply wash) is a machine designed to laundry, launder clothing. The term is mostly applied to machines that use water. Other ways of doing laundry include dry cleaning (which uses alternative cleaning fluids and is performed by specialist businesses) and ultrasonic cleaning. Modern-day home appliances use electric power to automatically clean clothes. The user adds laundry detergent, which is sold in liquid, powder, or dehydrated sheet form, to the wash water. The machines are also found in commercial laundromats where customers pay-per-use. History Washing by hand Laundering by hand involves soaking, beating, scrubbing, and rinsing dirty textiles. Before indoor plumbing, it was necessary to carry all the water used for washing, boiling, and rinsing the laundry from a pump, Water well, well, or Spring (hydrology), spring. Water for the laundry would be hand-carried, heated on a fire for washing, and then poured i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Book (audio CD Standard)
Compact Disc Digital Audio (CDDA or CD-DA), also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the '' Red Book'' technical specifications, which is why the format is also dubbed ''"Redbook audio"'' in some contexts. CDDA utilizes pulse-code modulation (PCM) and uses a 44,100 Hz sampling frequency and 16-bit resolution, and was originally specified to store up to 74 minutes of stereo audio per disc. The first commercially available audio CD player, the Sony CDP-101, was released in October 1982 in Japan. The format gained worldwide acceptance in 1983–84, selling more than a million CD players in its first two years, to play 22.5 million discs, before overtaking records and cassette tapes to become the dominant standard for commercial music. Peaking around year 2000, the audio CD contracted over the next decade due to rising popularity and revenue from digital downloading, and duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second
The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units (SI) is more precise: The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. As the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. The definition that is based on of a rotation of the earth is still used by the Universal Time 1 (UT1) system. Etymology "Minute" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
