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| {{Use dmy dates|date=July 2012}}
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| {{for|other types of power|Power (disambiguation)}}
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| {{Infobox physical quantity
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| | unit = [[watt]]
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| | symbols = ''P''
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| {{Classical mechanics}}
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| In [[physics]], '''power''' (symbol: ''P'') is defined as the amount of energy consumed per unit time. In the [[MKS system]], the unit of power is the [[joule]] per second (J/s), known as the [[watt]] (in honor of [[James Watt]], the eighteenth-century developer of the [[Watt steam engine|steam engine]]). For example, the rate at which a light bulb converts electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit time.<ref>{{Cite book|chapter= 6. Power|authors= Halliday and Resnick|title=Fundamentals of Physics|year= 1974}}</ref><ref>Chapter 13, § 3, pp 13-2,3 ''[[The Feynman Lectures on Physics]]'' Volume I, 1963</ref>
| | Ford has continually followed its yearn custom of producing the Charles Herbert Best Rudolf Diesel engine cars and in 2009 they did not disappoint with the creation of the Ford S-Goop diesel locomotive engine. Ford S-Liquid ecstasy Rudolf Diesel Locomotive engine is at once useable with a high pressure acting engine of 2.2-litre diesel .the newly 2.2-litre Duratorq TD Ci integrated into the Ford S-Max Rudolf Christian Karl Diesel Railway locomotive is matchless of the greatest and most hefty Rudolf Diesel engines currently useable in the automobile industriousness. It offers a almost sustained 400Nm of torsion superpower at 1750 rmp and a farther 420 NM of ephemeral all over boost that the requisite superpower and lightness for energising and surefooted passing manoeuvres. This is the paragon railroad car for professional and regular amateur drivers. The maximal great power that crapper be achieved by the Ford S-Max Diesel Engine of 175 PS is attained at 3500 rev. <br><br><br>Machine buyers get an fantabulous and uncommon alternative in the Ford S-Soap Diesel Locomotive engine that offers them greater tycoon take aim. The carrying into action of this item locomotive engine is impeccable. Efficiency whitethorn be the scoop give voice to key out the activities of this herculean engine. Since its advent the Ford Hermann Hueffer S-Scoop Rudolf Christian Karl Diesel Engine has forever delivered on the road. No automobile stays beforehand of you unless you desire to. The 2.2 cubic decimeter diesel engine railway locomotive fundament attain so many things for you; isolated from offering the highest locomotive big businessman it likewise provides the outflank fuel efficiency, Entropy that all but auto buyers are concerned to discover. <br><br><br>Diesel fire is by FAR cheaper than petrol and despite its disadvantages it remains the outdo fire of option peculiarly now, when nigh items swop at high pressure prices in the grocery store. By having diesel engine fuel and a effective locomotive that has a [http://Www.Thefreedictionary.com/estimable+fuel estimable fuel] thriftiness read and then you fire perch assured that your budget habit be stirred that a good deal in an endeavor to enjoy the joyousness of your elevator car. <br><br><br>The internal and outside studied of the Gerald Ford S-Goop Rudolf Christian Karl Diesel locomotive engine railway car is a goodness illustration of special artistic creation influence. The exterior reflects the favourable position of the railroad car and allows it insist authorization while its on the road. It is impressive to project how this machine scares away early models with its speed, acceleration, locomotive engine force and particular overtaking monaouervs. <br><br><br>The Edsel Bryant Ford S-Scoop Rudolf Diesel railroad car is fitted with Automatic headlights that chip in the number one wood decent visual modality to labour yet at the darkest hours of the Night. There are reflex wipers with rainfall sensor that Menachem Begin to form with the slightest or rather comportment of wet. Crossing S-Easy lay Rudolf Christian Karl Diesel has got Hold in and Tycoon operated and heated door mirrors with piddle lamps. On that point is also a Rump line conditioning to supply cooling system for your passengers. <br><br>Thurman Deaguero is an proficient in Ford S-Goop Diesel Locomotive. If you are concerned in erudition to a greater extent around caliber Ford S-Soap Engine, delight contact us by visiting our chief Crossing S-Grievous bodily harm Locomotive engine site: idealengines.co.uk or by career us at 442085960396<br><br>Should you loved this informative article and you want to receive more information relating to [http://www.200machinery.com/%E0%B8%A3%E0%B8%96%E0%B9%81%E0%B8%9A%E0%B8%84%E0%B9%82%E0%B8%AE/ แบคโฮ] please visit our own web-site. |
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| Energy transfer can be used to do [[Work (physics)|work]], so power is also the rate at which this work is performed. The same amount of work is done when carrying a load up a flight of stairs whether the person carrying it walks or runs, but more power is expended during the running because the work is done in a shorter amount of time. The output power of an electric motor is the product of the [[torque]] the motor generates and the angular velocity of its output shaft. The power expended to move a vehicle is the product of the traction force of the wheels and the velocity of the vehicle.
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| The integral of power over time defines the [[Work (physics)|work]] done. Because this integral depends on the trajectory of the point of application of the force and torque, this calculation of work is said to be [[Nonholonomic system|path dependent]].
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| ==Units==
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| [[File:Ansel Adams - National Archives 79-AAB-02.jpg|right|thumb|alt=Ansel Adams photograph of electrical wires of the Boulder Dam Power Units|Ansel Adams photograph of electrical wires of the Boulder Dam Power Units, 1941–1942]]
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| The dimension of power is energy divided by time. The [[International System of Units|SI]] unit of power is the [[watt]] (W), which is equal to one [[joule]] per second. Other units of power include [[erg]]s per second (erg/s), [[horsepower]] (hp), metric horsepower ([[horsepower#PS|Pferdestärke]] (PS) or [[horsepower#CV and cv|cheval vapeur]], CV), and [[foot-pound force|foot-pounds]] per minute. One horsepower is equivalent to 33,000 foot-pounds per minute, or the power required to lift 550 [[Pound (mass)|pounds]] by one foot in one second, and is equivalent to about 746 watts. Other units include [[dBm]], a relative logarithmic measure with 1 milliwatt as reference; (food) [[calorie]]s per hour (often referred to as [[kilocalorie]]s per hour); [[Btu]] per hour (Btu/h); and [[refrigeration ton|tons of refrigeration]] (12,000 Btu/h). | |
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| ==Average power==
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| As a simple example, burning a kilogram of [[coal]] releases much more energy than does detonating a kilogram of [[Trinitrotoluene|TNT]],<ref>Burning coal produces around 15-30 [[megajoule]]s per kilogram, while detonating TNT produces about 4.7 megajoules per kilogram. For the coal value, see {{cite web | last = Fisher | first = Juliya | title = Energy Density of Coal | work = The Physics Factbook | url = http://hypertextbook.com/facts/2003/JuliyaFisher.shtml|year=2003|accessdate =30 May 2011}} For the TNT value, see the article [[TNT equivalent]]. The coal value does not include the weight of oxygen used during combustion, while the TNT number if TNT only.</ref> but because the TNT reaction releases energy much more quickly, it delivers far more power than the coal.
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| If Δ''W'' is the amount of [[mechanical work|work]] performed during a period of [[time]] of duration Δ''t'', the '''average power''' ''P''<sub>avg</sub> over that period is given by the formula
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| :<math>
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| P_\mathrm{avg} = \frac{\Delta W}{\Delta t}\,.
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| </math>
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| It is the average amount of work done or energy converted per unit of time. The average power is often simply called "power" when the context makes it clear.
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| The '''instantaneous power''' is then the limiting value of the average power as the time interval Δ''t'' approaches zero.
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| :<math>
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| P = \lim _{\Delta t\rightarrow 0} P_\mathrm{avg} = \lim _{\Delta t\rightarrow 0} \frac{\Delta W}{\Delta t} = \frac{dW}{dt}\,.
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| </math>
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| In the case of constant power ''P'', the amount of work performed during a period of duration ''T'' is given by:
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| :<math>
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| W = PT\,.
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| </math>
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| In the context of energy conversion, it is more customary to use the symbol ''E'' rather than ''W''.
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| ==Mechanical power==
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| Power in mechanical systems is the combination of forces and movement. In particular, power is the product of a force on an object and the object's velocity, or the product of a torque on a shaft and the shaft's angular velocity.
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| Mechanical power is also described as the time derivative of work. In [[mechanics]], the [[mechanical work|work]] done by a force '''F''' on an object that travels along a curve ''C'' is given by the [[line integral]]:
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| : <math>W_C = \int_{C}\bold{F}\cdot \bold{v}dt =\int_{C} \bold{F} \cdot \mathrm{d}\bold{x},</math>
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| where '''x''' defines the path ''C'' and '''v''' is the velocity along this path.
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| If the force '''F''' is derivable from a potential, then applying the gradient theorem (and remembering that force is the negative of the gradient of the potential energy) yields:
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| :<math>W_C = U(B)-U(A),</math>
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| where ''A'' and ''B'' are the beginning and end of the path along which the work was done.
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| The power at any point along the curve ''C'' is the time derivative
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| :<math>P(t) = \frac{dW}{dt}=\bold{F}\cdot \bold{v}=-\frac{dU}{dt}.</math>
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| In one dimension, this can be simplified to:
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| :<math>P(t) = F\cdot v.</math>
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| In rotational systems, power is the product of the [[torque]] <var>τ</var> and [[angular velocity]] <var>ω</var>,
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| :<math>P(t) = \boldsymbol{\tau} \cdot \boldsymbol{\omega}, \,</math>
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| where '''ω''' measured in radians per second.
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| In fluid power systems such as hydraulic actuators, power is given by
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| :<math> P(t) = pQ, \!</math>
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| where ''p'' is [[pressure]] in [[pascal (unit)|pascals]], or N/m<sup>2</sup> and ''Q'' is [[volumetric flow rate]] in m<sup>3</sup>/s in SI units.
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| ===Mechanical advantage===
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| If a mechanical system has no losses then the input power must equal the output power. This provides a simple formula for the [[mechanical advantage]] of the system.
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| Let the input power to a device be a force ''F<sub>A</sub>'' acting on a point that moves with velocity ''v<sub>A</sub>'' and the output power be a force ''F<sub>B</sub>'' acts on a point that moves with velocity ''v<sub>B</sub>''. If there are no losses in the system, then
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| :<math>P = F_B v_B = F_A v_A, \!</math>
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| and the [[mechanical advantage]] of the system (output force per input force) is given by
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| : <math> \mathrm{MA} = \frac{F_B}{F_A} = \frac{v_A}{v_B}. </math>
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| The similar relationship is obtained for rotating systems, where ''T<sub>A</sub>'' and ''ω<sub>A</sub>'' are the torque and angular velocity of the input and ''T<sub>B</sub>'' and ''ω<sub>B</sub>'' are the torque and angular velocity of the output. If there are no losses in the system, then | |
| :<math>P = T_A \omega_A = T_B \omega_B, \!</math>
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| which yields the [[mechanical advantage]]
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| :<math> \mathrm{MA} = \frac{T_B}{T_A} = \frac{\omega_A}{\omega_B}.</math>
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| These relations are important because they define the maximum performance of a device in terms of [[velocity ratio]]s determined by its physical dimensions. See for example [[gear ratio]]s.
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| ==Power in optics==
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| In [[optics]], or [[radiometry]], the term ''power'' sometimes refers to [[radiant flux]], the average rate of energy transport by electromagnetic radiation, measured in [[watt]]s. In other contexts, it refers to [[optical power]], the ability of a [[lens (optics)|lens]] or other optical device to [[focus (optics)|focus]] light. It is measured in [[diopter]]s (inverse [[meter]]s), and equals the inverse of the [[focal length]] of the optical device.
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| ==Electrical power==
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| {{main|Electric power}}
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| The instantaneous electrical power ''P'' delivered to a component is given by
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| :<math>
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| P(t) = I(t) \cdot V(t) \,
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| </math>
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| where
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| :''P''(''t'') is the instantaneous power, measured in [[watt]]s ([[joule]]s per [[second]])
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| :''V''(''t'') is the [[potential difference]] (or voltage drop) across the component, measured in [[volt]]s
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| :''I''(''t'') is the [[Electric current|current]] through it, measured in [[ampere]]s
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| If the component is a [[resistor]] with time-invariant [[voltage]] to [[electric current|current]] ratio, then:
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| :<math>
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| P=I \cdot V = I^2 \cdot R = \frac{V^2}{R} \,
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| </math> | |
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| where
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| :<math>
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| R = \frac{V}{I} \,
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| </math>
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| is the [[electrical resistance|resistance]], measured in [[ohm]]s. | |
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| ==Peak power and duty cycle==
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| [[File:peak-power-average-power-tau-T.png|right|thumb|right|In a train of identical pulses, the instantaneous power is a periodic function of time. The ratio of the pulse duration to the period is equal to the ratio of the average power to the peak power. It is also called the duty cycle (see text for definitions).]]
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| In the case of a periodic signal <math>s(t)</math> of period <math>T</math>, like a train of identical pulses, the instantaneous power <math>p(t) = |s(t)|^2</math> is also a periodic function of period <math>T</math>. The ''peak power'' is simply defined by:
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| :<math>
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| P_0 = \max [p(t)]
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| </math>. | |
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| The peak power is not always readily measurable, however, and the measurement of the average power <math>P_\mathrm{avg}</math> is more commonly performed by an instrument. If one defines the energy per pulse as:
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| :<math>
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| \epsilon_\mathrm{pulse} = \int_{0}^{T}p(t) \mathrm{d}t \,
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| </math>
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| then the average power is:
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| :<math>
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| P_\mathrm{avg} = \frac{1}{T} \int_{0}^{T}p(t) \mathrm{d}t = \frac{\epsilon_\mathrm{pulse}}{T} \,
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| </math>.
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| One may define the pulse length <math>\tau</math> such that <math>P_0\tau = \epsilon_\mathrm{pulse}</math> so that the ratios
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| :<math>
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| \frac{P_\mathrm{avg}}{P_0} = \frac{\tau}{T} \,
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| </math>
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| are equal. These ratios are called the ''duty cycle'' of the pulse train.
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| ==See also==
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| * [[Simple machines]]
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| * [[Mechanical advantage]]
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| * [[Motive power]]
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| * [[Orders of magnitude (power)]]
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| * [[Pulsed power]]
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| * [[Intensity (physics)|Intensity]] — in the radiative sense, power per area
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| * [[Power gain]] — for linear, two-port networks.
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| ==References==
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| <references/>
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| [[Category:Concepts in physics]]
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| [[Category:Power (physics)| ]]
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>
Ford has continually followed its yearn custom of producing the Charles Herbert Best Rudolf Diesel engine cars and in 2009 they did not disappoint with the creation of the Ford S-Goop diesel locomotive engine. Ford S-Liquid ecstasy Rudolf Diesel Locomotive engine is at once useable with a high pressure acting engine of 2.2-litre diesel .the newly 2.2-litre Duratorq TD Ci integrated into the Ford S-Max Rudolf Christian Karl Diesel Railway locomotive is matchless of the greatest and most hefty Rudolf Diesel engines currently useable in the automobile industriousness. It offers a almost sustained 400Nm of torsion superpower at 1750 rmp and a farther 420 NM of ephemeral all over boost that the requisite superpower and lightness for energising and surefooted passing manoeuvres. This is the paragon railroad car for professional and regular amateur drivers. The maximal great power that crapper be achieved by the Ford S-Max Diesel Engine of 175 PS is attained at 3500 rev.
Machine buyers get an fantabulous and uncommon alternative in the Ford S-Soap Diesel Locomotive engine that offers them greater tycoon take aim. The carrying into action of this item locomotive engine is impeccable. Efficiency whitethorn be the scoop give voice to key out the activities of this herculean engine. Since its advent the Ford Hermann Hueffer S-Scoop Rudolf Christian Karl Diesel Engine has forever delivered on the road. No automobile stays beforehand of you unless you desire to. The 2.2 cubic decimeter diesel engine railway locomotive fundament attain so many things for you; isolated from offering the highest locomotive big businessman it likewise provides the outflank fuel efficiency, Entropy that all but auto buyers are concerned to discover.
Diesel fire is by FAR cheaper than petrol and despite its disadvantages it remains the outdo fire of option peculiarly now, when nigh items swop at high pressure prices in the grocery store. By having diesel engine fuel and a effective locomotive that has a estimable fuel thriftiness read and then you fire perch assured that your budget habit be stirred that a good deal in an endeavor to enjoy the joyousness of your elevator car.
The internal and outside studied of the Gerald Ford S-Goop Rudolf Christian Karl Diesel locomotive engine railway car is a goodness illustration of special artistic creation influence. The exterior reflects the favourable position of the railroad car and allows it insist authorization while its on the road. It is impressive to project how this machine scares away early models with its speed, acceleration, locomotive engine force and particular overtaking monaouervs.
The Edsel Bryant Ford S-Scoop Rudolf Diesel railroad car is fitted with Automatic headlights that chip in the number one wood decent visual modality to labour yet at the darkest hours of the Night. There are reflex wipers with rainfall sensor that Menachem Begin to form with the slightest or rather comportment of wet. Crossing S-Easy lay Rudolf Christian Karl Diesel has got Hold in and Tycoon operated and heated door mirrors with piddle lamps. On that point is also a Rump line conditioning to supply cooling system for your passengers.
Thurman Deaguero is an proficient in Ford S-Goop Diesel Locomotive. If you are concerned in erudition to a greater extent around caliber Ford S-Soap Engine, delight contact us by visiting our chief Crossing S-Grievous bodily harm Locomotive engine site: idealengines.co.uk or by career us at 442085960396
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