Power - Revision history

Jmdonev: 1 revision imported

2021-09-27T00:02:40Z

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energy>Ethan.boechler at 19:42, 10 September 2021

2021-09-10T19:42:44Z

← Older revision		Revision as of 19:42, 10 September 2021
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	~~[[Category:Done 2020-05-30]]~~
	[[category:physics concepts]]		[[category:physics concepts]]
	[[category:371 topics]]		[[category:371 topics]]
	<onlyinclude>Power is how fast energy is transformed or transmitted.</onlyinclude> To make an analogy: if [[energy]] is like money, power is a wage or salary (e.g., $18/hour or $50,000/year), or usage rate (e.g, spending $20/hour to rent a canoe or $1500/month on rent).		[[Category:Done 2021-01-31]]
			[[Category:Translated to Spanish]]
			[[es:Potencia]]
			[[Category:Translated to French]]
			[[fr:Puissance]]
			<onlyinclude>Power is how fast energy is transformed or transmitted.</onlyinclude> To make an analogy: if [[energy]] is like money, power is a wage or salary (e.g., earning $18/hour or $50,000/year), or usage rate (e.g, spending $20/hour to rent a canoe or $1500/month on rent).

	Power can be expressed in many different [[units]], all of which can be expressed as a unit of energy divided by a unit of time. The most common unit is the [[watt]] (W), defined as 1 [[joule]] (J) of energy per second. A 40 W [[light bulb]], then, uses 40 J of [[electrical energy]] every [[second]] to stay lit.<ref name=Knight>R. D. Knight, "Work," in ''Physics for Scientists and Engineers: A Strategic Approach,'' 2nd ed. San Francisco, U.S.A.: Pearson Addison-Wesley, 2008, pp. 325–327</ref> The average power output of the human body during moderate exercise is about 100 W.<ref>R. Wolfson, "High-Energy Society," in ''Energy, Environment and Climate,'' 2nd ed. New York, U.S.A.: Norton, 2012, pp. 20–21</ref>		Power can be expressed in many different [[units]], all of which can be expressed as a unit of energy divided by a unit of time. The most common unit is the [[watt]] (W), defined as 1 [[joule]] (J) of energy per second. A 40 W [[light bulb]], then, uses 40 J of [[electrical energy]] every [[second]] to stay lit.<ref name=Knight>R. D. Knight, "Work," in ''Physics for Scientists and Engineers: A Strategic Approach,'' 2nd ed. San Francisco, U.S.A.: Pearson Addison-Wesley, 2008, pp. 325–327</ref> The average power output of the human body during moderate exercise is about 100 W.<ref>R. Wolfson, "High-Energy Society," in ''Energy, Environment and Climate,'' 2nd ed. New York, U.S.A.: Norton, 2012, pp. 20–21</ref>
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	The relationship between power, [[energy]], and time can be described by the following equation<ref name=Knight/>:		The relationship between power, [[energy]], and time can be described by the following equation<ref name=Knight/>:

	<center><math>P = \frac{\Delta E_{sys}}{\Delta t}</math></center>		<center><math>P=\frac{\Delta E_{sys}}{\Delta t}</math></center>

	:::* ''P'' is the average power output, measured in watts (W)		:::* ''P'' is the average power output, measured in watts (W)
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	Please see below to convert among various units for power:		Please see below to convert among various units for power:

	<html><br /> <iframe src="https://energyeducation.ca/simulations/converter/converter.php?defaultMeasure=Power&defaultFrom=~~Watts~~&defaultTo=horsepower" width="750" height="200"> </iframe><br /> </html>		<html><br /> <iframe src="https://energyeducation.ca/simulations/converter/converter.php?defaultMeasure=Power&defaultFrom=watt&defaultTo=horsepower" width="750" height="200"> </iframe><br /> </html>

	==For Further Reading==		==For Further Reading==

Jmdonev at 21:22, 28 June 2020

2020-06-28T21:22:36Z

← Older revision		Revision as of 21:22, 28 June 2020
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	[[category:physics concepts]]		[[category:physics concepts]]
	[[category:371 topics]]		[[category:371 topics]]
	~~[[category:Lecture 2A High energy society]]~~		<onlyinclude>Power is how fast energy is transformed or transmitted.</onlyinclude> To make an analogy: if [[energy]] is like money, power is a wage or salary (e.g., $18/hour or $50,000/year), or usage rate (e.g, spending $20/hour to rent a canoe or $1500/month on rent).
	<onlyinclude>Power is how fast energy is ~~used~~ or ~~transferred~~.</onlyinclude> To make an analogy: if [[energy]] is like money, power is a wage or salary (e.g., $18/hour or $50,000/year), or usage rate (e.g, $20/hour or $~~500~~/month).

	Power can be expressed in many different [[units]], all of which can be expressed as a unit of energy divided by a unit of time. The most common unit is the [[watt]] (W), defined as 1 [[joule]] (J) of energy per second. A 40 W [[light bulb]], then, uses 40 J of [[electrical energy]] every [[second]] to stay lit.<ref name=Knight>R. D. Knight, "Work," in ''Physics for Scientists and Engineers: A Strategic Approach,'' 2nd ed. San Francisco, U.S.A.: Pearson Addison-Wesley, 2008, pp. 325–327</ref> The average power output of the human body during moderate exercise is about 100 W.<ref>R. Wolfson, "High-Energy Society," in ''Energy, Environment and Climate,'' 2nd ed. New York, U.S.A.: Norton, 2012, pp. 20–21</ref>		Power can be expressed in many different [[units]], all of which can be expressed as a unit of energy divided by a unit of time. The most common unit is the [[watt]] (W), defined as 1 [[joule]] (J) of energy per second. A 40 W [[light bulb]], then, uses 40 J of [[electrical energy]] every [[second]] to stay lit.<ref name=Knight>R. D. Knight, "Work," in ''Physics for Scientists and Engineers: A Strategic Approach,'' 2nd ed. San Francisco, U.S.A.: Pearson Addison-Wesley, 2008, pp. 325–327</ref> The average power output of the human body during moderate exercise is about 100 W.<ref>R. Wolfson, "High-Energy Society," in ''Energy, Environment and Climate,'' 2nd ed. New York, U.S.A.: Norton, 2012, pp. 20–21</ref>

	For most [[engine]]s and [[power plant]]s there are two different powers. The rate at which energy is coming into the [[system]] from the [[fuel]] is the [[thermal power]]. The amount of power that the [[engine]] is outputting is the [[mechanical power]]. For a power ~~pant~~, this output is [[electricity]] so it's measured in [[megawatts electric]] (MWe) as opposed to the input power which is measured in [[megawatts thermal]] (MWt).		For most [[engine]]s and [[power plant]]s there are two different powers. The rate at which energy is coming into the [[system]] from the [[fuel]] is the [[thermal power]]. The amount of power that the [[engine]] is outputting is the [[mechanical power]]. For a power plant, this output is [[electricity]] so it's measured in [[megawatts electric]] (MWe) as opposed to the input power which is measured in [[megawatts thermal]] (MWt).
	==Energy and Power==		==Energy and Power==

Jmdonev at 21:21, 28 June 2020

2020-06-28T21:21:45Z

← Older revision		Revision as of 21:21, 28 June 2020
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	[[Category:Done ~~2018~~-06-15]]		[[Category:Done 2020-05-30]]
	[[category:physics concepts]]		[[category:physics concepts]]
	[[category:371 topics]]		[[category:371 topics]]

Jmdonev: 1 revision imported

2018-06-25T14:30:35Z

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Jmdonev at 19:17, 24 June 2018

2018-06-24T19:17:35Z

← Older revision		Revision as of 19:17, 24 June 2018
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	[[Category:Done ~~2017~~-07-01]]		[[Category:Done 2018-06-15]]
	[[category:physics concepts]]		[[category:physics concepts]]
	[[category:371 topics]]		[[category:371 topics]]
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	Please see below to convert among various units for power:		Please see below to convert among various units for power:

	<html><br /> <iframe src="~~http~~://energyeducation.ca/simulations/converter/converter.php?defaultMeasure=Power&defaultFrom=Watts&defaultTo=horsepower" width="750" height="200"> </iframe><br /> </html>		<html><br /> <iframe src="https://energyeducation.ca/simulations/converter/converter.php?defaultMeasure=Power&defaultFrom=Watts&defaultTo=horsepower" width="750" height="200"> </iframe><br /> </html>

			==For Further Reading==
			*[[Energy]]
			*[[End use energy]]
			*[[Primary energy]]
			*[[Energy conversion technology]]
			*Or explore a [[Special:Random\|random page]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

Jmdonev: 1 revision imported

2017-08-29T01:47:22Z

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Jmdonev at 22:18, 16 August 2017

2017-08-16T22:18:10Z

← Older revision		Revision as of 22:18, 16 August 2017
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	The relationship between power, [[energy]], and time can be described by the following equation<ref name=Knight/>:		The relationship between power, [[energy]], and time can be described by the following equation<ref name=Knight/>:

	<m>P = \frac{\Delta E_{sys}}{\Delta t}</m>		<center><math>P = \frac{\Delta E_{sys}}{\Delta t}</math></center>

	:::* ''P'' is the average power output, measured in watts (W)		:::* ''P'' is the average power output, measured in watts (W)
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	\| 100W \|\| 3 s \|\| 300 J		\| 100W \|\| 3 s \|\| 300 J
	\|}		\|}

	==Power Unit Conversion==		==Power Unit Conversion==
	Please see below to convert among various units for power:		Please see below to convert among various units for power:

J.williams: 1 revision imported

2015-09-18T16:51:11Z

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Jmdonev at 18:20, 4 September 2015

2015-09-04T18:20:30Z

← Older revision		Revision as of 18:20, 4 September 2015
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	<onlyinclude>Power is how fast energy is used or transferred.</onlyinclude> To make an analogy: if [[energy]] is like money, power is a wage or salary (e.g., $18/hour or $50,000/year), or usage rate (e.g, $20/hour or $500/month).		<onlyinclude>Power is how fast energy is used or transferred.</onlyinclude> To make an analogy: if [[energy]] is like money, power is a wage or salary (e.g., $18/hour or $50,000/year), or usage rate (e.g, $20/hour or $500/month).

	Power can be expressed in many different units, all of which can be expressed as a unit of energy divided by a unit of time. The most common unit is the [[watt]] (W), defined as 1 [[joule]] (J) of energy per second. A 40 W light bulb, then, uses 40 J of electrical energy every second to stay lit.<ref name=Knight>R. D. Knight, "Work," in ''Physics for Scientists and Engineers: A Strategic Approach,'' 2nd ed. San Francisco, U.S.A.: Pearson Addison-Wesley, 2008, pp. 325–327</ref> The average power output of the human body during moderate exercise is about 100 W.<ref>R. Wolfson, "High-Energy Society," in ''Energy, Environment and Climate,'' 2nd ed. New York, U.S.A.: Norton, 2012, pp. 20–21</ref>		Power can be expressed in many different [[units]], all of which can be expressed as a unit of energy divided by a unit of time. The most common unit is the [[watt]] (W), defined as 1 [[joule]] (J) of energy per second. A 40 W [[light bulb]], then, uses 40 J of [[electrical energy]] every [[second]] to stay lit.<ref name=Knight>R. D. Knight, "Work," in ''Physics for Scientists and Engineers: A Strategic Approach,'' 2nd ed. San Francisco, U.S.A.: Pearson Addison-Wesley, 2008, pp. 325–327</ref> The average power output of the human body during moderate exercise is about 100 W.<ref>R. Wolfson, "High-Energy Society," in ''Energy, Environment and Climate,'' 2nd ed. New York, U.S.A.: Norton, 2012, pp. 20–21</ref>

	For most [[engine]]s and [[power plant]]s there are two different powers. The rate at which energy is coming into the [[system]] from the fuel is the [[thermal power]]. The amount of power that the engine is outputting is the [[mechanical power]]. For a power pant, this output is [[electricity]] so it's measured in [[megawatts electric]] (MWe) as opposed to the input power which is measured in [[megawatts thermal]] (MWt).		For most [[engine]]s and [[power plant]]s there are two different powers. The rate at which energy is coming into the [[system]] from the [[fuel]] is the [[thermal power]]. The amount of power that the [[engine]] is outputting is the [[mechanical power]]. For a power pant, this output is [[electricity]] so it's measured in [[megawatts electric]] (MWe) as opposed to the input power which is measured in [[megawatts thermal]] (MWt).
	==Energy and Power==		==Energy and Power==

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	:::* ''Δt'' is the duration - how long the energy use takes - measured in seconds (s)		:::* ''Δt'' is the duration - how long the energy use takes - measured in seconds (s)

	Since power is a ''rate'' of energy use (energy divided by an interval of time), multiplying a unit of power by a unit of time will give a quantity of energy. One such example is in the energy unit kilowatt-~~hours~~ (kWh). A kilowatt is equal to 1000 watts, so 1 kWh represents the amount of energy transfer that occurs over one hour from a power output of 1000 watts (i.e., joules per second). Thus 1 kWh is equal to 3,600,000 joules of energy transfer (work).		Since power is a ''rate'' of energy use (energy divided by an interval of time), multiplying a unit of power by a unit of time will give a quantity of energy. One such example is in the energy unit [[kilowatt-hour]]s (kWh). A kilowatt is equal to 1000 watts, so 1 kWh represents the amount of energy transfer that occurs over one hour from a power output of 1000 watts (i.e., joules per second). Thus 1 kWh is equal to 3,600,000 joules of energy transfer (work).

	More power can accomplish a task with a given energy requirement in a shorter time. For example, lifting a 15 kg block 2 [[meter]]s in the air. This task requires approximately 300 J of energy input (work). A [[electric motor\|motor]] and [[pulley]] system with a 5 W power output could accomplish this task in one minute. However, a more powerful motor with an output of 100 W could raise the box to the same height in just three seconds! But in the end, both motors will have done the same amount of work (energy transfer) in lifting the box.		More power can accomplish a task with a given energy requirement in a shorter time. For example, lifting a 15 kg block 2 [[meter]]s in the [[air]]. This task requires approximately 300 J of energy input (work). A [[electric motor\|motor]] and [[pulley]] system with a 5 W power output could accomplish this task in one minute. However, a more powerful motor with an output of 100 W could raise the box to the same height in just three seconds! But in the end, both motors will have done the same amount of work (energy transfer) in lifting the box.

	{\| class="wikitable"		{\| class="wikitable"