"distance vector and a force vector. Torque and energy are related to one another by the equation where ""E"" is energy, ""τ"" is (the vector magnitude of) torque, and ""θ"" is the angle swept (in radians). Since radians are dimensionless, it follows that torque and energy have the same dimensions. One joule in everyday life represents approximately: Since the joule is also a watt-second and the common unit for electricity sales to homes is the kW⋅h (kilowatt-hour), a kW⋅h is thus 1000 W × 3600 s = 3.6 MJ (megajoules). 1 joule is equal to (approximately unless otherwise stated): Units"
"Joule The joule (; symbol: J) is a derived unit of energy in the International System of Units. It is equal to the energy transferred to (or work done on) an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre (1 newton metre or N⋅m). It is also the energy dissipated as heat when an electric current of one ampere passes through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule (1818–1889). In terms firstly of base"
"per second. A similar analogy does not apply to the expression kg∙m∙ s because the units kg∙m in the numerator have no physical meaning like the numerators of distance and energy shown in these examples. The joule-second also appears as the unit of measure in classical mechanics for the angular momentum of a rotating object and in quantum mechanics within the definition of Planck's constant. Angular momentum is the product of an object’s moment of inertia, in units of kg∙m and its rotational velocity in units of m∙s∙m, or simply s (i.e., Hz). This product of moment of inertia and"
"Joule-second The joule-second (J s, or J∙s) is the mathematical product of an SI Derived Unit, the joule (J), and an SI Base Unit, the second (s). The joule-second describes the amount of action occurring in a physical system through a summation of energy (or heat, or work) over time. In mathematical terms, this summation of energy means that the quantity of energy becomes integrated over time to give a number - an answer to the question. In SI base units the joule-second becomes kilogram-meters squared-per second or kg∙m∙ s. Dimensional Analysis of the joule-second yields M L T. Note"
"Units of energy Because energy is defined via work, the SI unit for energy is the same as the unit of work – the joule (J), named in honor of James Prescott Joule and his experiments on the mechanical equivalent of heat. In slightly more fundamental terms, 1 joule is equal to 1 newton metre and, in terms of SI base units An energy unit that is used in atomic physics, particle physics and high energy physics is the electronvolt (eV). One eV is equivalent to 1.60217653×10 J. In spectroscopy the unit cm = 0.000123986 eV is used to represent"
"to energy, namely time. In 1843, James Prescott Joule independently discovered the mechanical equivalent in a series of experiments. The most famous of them used the ""Joule apparatus"": a descending weight, attached to a string, caused rotation of a paddle immersed in water, practically insulated from heat transfer. It showed that the gravitational potential energy lost by the weight in descending was equal to the internal energy gained by the water through friction with the paddle. In the International System of Units (SI), the unit of energy is the joule, named after James Prescott Joule. It is a derived unit."
"Joule per mole The joule per mole (symbol: J·mole or J/mol) is an SI derived unit of energy per amount of material. Energy is measured in joules, and the amount of material is measured in moles. For example, Gibbs free energy is quantified as joules per mole. Since 1 mole = 6.02214179×10 particles (atoms, molecules, ions etc.), 1 Joule per mole is equal to 1 Joule divided by 6.02214179×10 particles, or (6.022×10^23 particles/mole), 1.66054×10 Joule per particle. This very small amount of energy is often expressed in terms of a smaller unit such as the electronvolt (eV, see below). Physical"
"the denominator of seconds (s) in the base units. The joule-second ""should not be confused"" with the physical process of joules per second (J/s). In legitimate physical processes, when the unit of time appears in the denominator of a ratio, the described process occurs at a rate. For example, in discussions about speed, an object like a car travels a known distance of kilometers spread over a known number of seconds, and the car’s rate of speed becomes kilometers per second (km/s). In physics, work per time describes a system’s power; defined by the units of Watts (J/s), or joules"
"Metre per second Metre per second (American English: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds. The SI unit symbols are m·s, m s, m/s, or , sometimes (unofficially) abbreviated as . Where metres per second are several orders of magnitude too slow to be convenient, such as in astronomical measurements, velocities may be given in kilometres per second, where is 1000 metres per second, sometimes unofficially abbreviated as ""kps"". is equivalent to: 1"
"rotational velocity yields kg∙m∙ s or the joule-second. Planck's constant represents the energy of a wave, in units of joule, divided by the frequency of that wave, in units of s. This quotient of energy and frequency also yields the joule-second (J∙s). Joule-second The joule-second (J s, or J∙s) is the mathematical product of an SI Derived Unit, the joule (J), and an SI Base Unit, the second (s). The joule-second describes the amount of action occurring in a physical system through a summation of energy (or heat, or work) over time. In mathematical terms, this summation of energy means"
"second per second for acceleration, and per second for frequency. Although the historical definition of the unit was based on this division of the Earth's rotation cycle, the formal definition in the International System of Units (SI) is a much steadier timekeeper: 1 second is defined to be exactly ""the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom"" (at a temperature of 0 K). Because the Earth's rotation varies and is also slowing ever so slightly, a leap second is periodically added to clock"
"the order of 10 kJ·mol, bond energies are of the order of 100 kJ·mol, and ionization energies of the order of 1000 kJ·mol. 1 kJ·mol is equal to 0.239 kcal·mol or 1.04×10 eV per particle. At room temperature (25 °C, 77 °F, or 298.15 K) 1 kJ·mol is equal to 0.4034 formula_1. Joule per mole The joule per mole (symbol: J·mole or J/mol) is an SI derived unit of energy per amount of material. Energy is measured in joules, and the amount of material is measured in moles. For example, Gibbs free energy is quantified as joules per mole. Since"
"Becquerel The becquerel (; symbol: Bq) is the SI derived unit of radioactivity. One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. The becquerel is therefore equivalent to an inverse second, s. The becquerel is named after Henri Becquerel, who shared a Nobel Prize in Physics with Pierre and Marie Curie in 1903 for their work in discovering radioactivity. As with every International System of Units (SI) unit named for a person, the first letter of its symbol is uppercase (Bq). However, when an SI unit is spelled out"
"= r × F. Therefore, torque on a particle is ""equal"" to the first derivative of its angular momentum with respect to time. If multiple forces are applied, Newton's second law instead reads , and it follows that This is a general proof. Torque has dimension force times distance, symbolically . Official SI literature suggests using the unit ""newton metre"" (N⋅m) or the unit ""joule per radian"". The unit ""newton metre"" is properly denoted N⋅m or N m. This avoids ambiguity with mN, millinewtons. The SI unit for energy or work is the joule. It is dimensionally equivalent to a"
"Inch per second The inch per second is a unit of speed or velocity. It expresses the distance in inches (""in"") traveled or displaced, divided by time in seconds (""s"", or ""sec""). The equivalent SI unit is the metre per second. Abbreviations include in/s, in/sec, ips, and less frequently in s. 1 inch per second is equivalent to: 1 metre per second ≈ 39.370079 inches per second (approximately)<br> 1 foot per second = 12 inches per second (exactly)<br> 1 mile per hour = 17.6 inches per second (exactly)<br> 1 kilometre per hour ≈ 10.936133 inches per second (approximately) In magnetic"
"Radian per second The radian per second (symbol: rad·s or rad/s) is the SI unit of rotational speed (angular velocity), commonly denoted by the Greek letter ""ω"" (omega). The radian per second is also the unit of angular frequency. The radian per second is defined as the change in the orientation of an object, in radians, every second. Since the radian is a dimensionless unit, the radian per second is dimensionally equivalent to the hertz—both are defined as s. This may lead to confusion between the quantities angular frequency ""ω"" and frequency ""ν"". A use of the ""unit radian per"
"one joule of energy per coulomb of charge that passes through it. It can be expressed in terms of SI base units (m, kg, s, and A) as It can also be expressed as amperes times ohms (current times resistance, Ohm's law), watts per ampere (power per unit current, definition of electric power), or joules per coulomb (energy per unit charge), which is also equivalent to electronvolts per elementary charge: The ""conventional"" volt, V, defined in 1988 by the 18th General Conference on Weights and Measures and in use from 1990, is implemented using the Josephson effect for exact frequency-to-voltage"
"the IPK is crucial because the kilogram underpins much of the SI system of measurement as it is currently defined and structured. For instance, the newton is defined as the force necessary to accelerate one kilogram at one metre per second squared. If the mass of the IPK were to change slightly then the newton would also change proportionally. In turn, the pascal, the SI unit of pressure, is defined in terms of the newton. This chain of dependency follows to many other SI units of measure. For instance, the joule, the SI unit of energy, is defined as that"
"unit of acceleration is formula_19 or metre per second squared. If formula_20 is the average acceleration and formula_21 is the average velocity over the time interval formula_9 then mathematically, formula_23 The instantaneous acceleration is the limit of the ratio formula_24 and formula_9 as formula_9 approaches zero i.e., formula_27 formula_28 The rate of change of acceleration, the third derivative of displacement is known as jerk. The SI unit of jerk is formula_29. In the UK jerk is also known as jolt. The rate of change of jerk, the fourth derivative of displacement is known as jounce. The SI unit of jounce"
"Gal (unit) The gal (symbol: Gal), sometimes called galileo after Galileo Galilei, is a unit of acceleration used extensively in the science of gravimetry. The gal is defined as 1 centimeter per second squared (1 cm/s). The milligal (mGal) and microgal (µGal) refer respectively to one thousandth and one millionth of a gal. The gal is not part of the International System of Units (known by its French-language initials ""SI""). In 1978 the CIPM decided that it was permissible to use the gal ""with the SI until the CIPM considers that [its] use is no longer necessary"". However, use of"
"Poise (unit) The poise (symbol P; ) is the unit of dynamic viscosity (absolute viscosity) in the centimetre–gram–second system of units. It is named after Jean Léonard Marie Poiseuille (see Hagen–Poiseuille equation). The analogous unit in the International System of Units is the pascal-second (Pa⋅s): The poise is often used with the metric prefix ""centi-"" because the viscosity of water at 20 °C (NTP) is almost exactly 1 centipoise. A centipoise is one hundredth of a poise, or one millipascal-second (mPa⋅s) in SI units (1 cP = 10 Pa⋅s = 1 mPa⋅s). The CGS symbol for the centipoise is cP."
"foot per second = (exactly) 1 mile per hour = (exactly) 1 km/h = (exactly) 1 kilometre per second is equivalent to: The benz, named in honour of Karl Benz, has been proposed as a name for one metre per second. Although it has seen some support as a practical unit, primarily from German sources, it was rejected as the SI unit of velocity and has not seen widespread use or acceptance. Metre per second Metre per second (American English: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude"
"units, of which the main ones are ESU, Gaussian, and EMU. Among these, there are two alternative (non-equivalent) units of magnetic dipole moment: where statA is statamperes, cm is centimeters, erg is ergs, and G is gauss. The ratio of these two non-equivalent CGS units (EMU/ESU) is equal to the speed of light in free space, expressed in cm⋅s. All formulae in this article are correct in SI units; they may need to be changed for use in other unit systems. For example, in SI units, a loop of current with current and area has magnetic moment (see below), but"
"equal to small calories. Although these units relate to the metric system, all of them have been considered obsolete in science since the adoption of the SI system. The unit of energy in the International System of Units is the joule. One small calorie is approximately 4.2 joules (so one large calorie is about 4.2 kilojoules). The factor used to convert calories to joules at a given temperature is numerically equivalent to the specific heat capacity of water expressed in joules per kelvin per gram (or per kilogram, for kilocalories). The precise conversion factor depends on the definition adopted. In"
"more random conditions as entropy increases. The SI unit of force is the newton (symbol N), which is the force required to accelerate a one kilogram mass at a rate of one meter per second squared, or . The corresponding CGS unit is the dyne, the force required to accelerate a one gram mass by one centimeter per second squared, or . A newton is thus equal to 100,000 dynes. The gravitational foot-pound-second English unit of force is the pound-force (lbf), defined as the force exerted by gravity on a pound-mass in the standard gravitational field of . The pound-force"
"Metre per second squared The metre per second squared is the unit of acceleration in the International System of Units (SI). As a derived unit, it is composed from the SI base units of length, the metre, and time, the second. Its symbol is written in several forms as m/s, m·s or m s, or less commonly, as m/s/s. As acceleration, the unit is interpreted physically as change in velocity or speed per time interval, i.e. metre per second per second and is treated as a vector quantity. An object experiences a constant acceleration of one metre per second squared"
"use of equivalent dose as a separate protection quantity. This would avoid confusion between equivalent dose, effective dose and dose equivalent, and to use absorbed dose in Gy as a more appropriate quantity for limiting deterministic effects to the eye lens, skin, hands & feet. These proposals will need to go through the following stages: The SI unit of measure for equivalent dose is the sievert, defined as one Joule per kg. In the United States the roentgen equivalent man (rem), equal to 0.01 sievert, is still in common use, although regulatory and advisory bodies are encouraging transition to sieverts."
"units of measure for the signal energy formula_1 would appear as volt·seconds, which is ""not"" dimensionally correct for energy in the sense of the physical sciences. After dividing formula_1 by ""Z"", however, the dimensions of ""E"" would become volt·seconds per ohm, which is equivalent to joules, the SI unit for energy as defined in the physical sciences. Similarly, the spectral energy density of signal x(t) is where ""X""(""f"") is the Fourier transform of ""x""(""t""). For example, if ""x""(""t"") represents the magnitude of the electric field component (in volts per meter) of an optical signal propagating through free space, then the"
"higher SI unit is 1000 times larger, times of 10 and 10 seconds are typically expressed as tens or hundreds of femtoseconds. Femtosecond A femtosecond is the SI unit of time equal to 10 or / of a second; that is, one quadrillionth, or one millionth of one billionth, of a second. For context, a femtosecond is to a second as a second is to about 31.71 million years; a ray of light travels approximately 0.3 µm (micrometers) in 1 femtosecond, a distance comparable to the diameter of a virus. The word ""femtosecond"" is formed by the SI prefix ""femto"""
"Statmho The statmho is the unit of electrical conductance in the electrostatic system of units (ESU), an extension of the centimeter-gram-second (CGS) system to cover electrical units. In the ESU system, the permittivity of free space is set to unity by definition. This results in unit conversions to the SI system containing a power of the speed of light, ""c"", as well as a power of 10. In the case of the statmho, the conversion from siemens (S) is given by: 1 S ≡ 10""c"" statmho The value of ""c"" in the SI system is 299,792,458 metres per second exactly"
"since superseded). This proposal is not yet accepted as part of the SI. Coulomb The coulomb (symbol: C) is the International System of Units (SI) unit of electric charge. It is the charge (symbol: ""Q"" or ""q"") transported by a constant current of one ampere in one second: Thus, it is also the amount of excess charge on a capacitor of one farad charged to a potential difference of one volt: The coulomb is equivalent to the charge of approximately ( mol) protons, and −1 C is equivalent to the charge of approximately electrons. A new definition, in terms of"
"a gram of potassium is 30 Bq. The following table shows radiation quantities in SI and non-SI units. Becquerel The becquerel (; symbol: Bq) is the SI derived unit of radioactivity. One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. The becquerel is therefore equivalent to an inverse second, s. The becquerel is named after Henri Becquerel, who shared a Nobel Prize in Physics with Pierre and Marie Curie in 1903 for their work in discovering radioactivity. As with every International System of Units (SI) unit named for a"
"Impulse (physics) In classical mechanics, impulse (symbolized by J or Imp) is the integral of a force, F, over the time interval, t, for which it acts. Since force is a vector quantity, impulse is also a vector in the same direction. Impulse applied to an object produces an equivalent vector change in its linear momentum, also in the same direction. The SI unit of impulse is the newton second (N⋅s), and the dimensionally equivalent unit of momentum is the kilogram meter per second (kg⋅m/s). The corresponding English engineering units are the pound-second (lbf⋅s) and the slug-foot per second (slug⋅ft/s)."