Energy vs power - Revision history

Jmdonev: 1 revision imported

2021-09-27T00:03:17Z

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energy>Ethan.boechler at 16:55, 13 September 2021

2021-09-13T16:55:27Z

← Older revision		Revision as of 16:55, 13 September 2021
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	[[category:371 topics]]		[[category:371 topics]]
	[[category:Lecture 2A High energy society]]		[[category:Lecture 2A High energy society]]
			[[Category:Translated to French]]
			[[fr:Énergie vs puissance]]
	[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: Lifting a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. Lifting faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]		[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: Lifting a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. Lifting faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]
	<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>		<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>

Jmdonev at 20:48, 4 September 2019

2019-09-04T20:48:49Z

← Older revision		Revision as of 20:48, 4 September 2019
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	[[category:371 topics]]		[[category:371 topics]]
	[[category:Lecture 2A High energy society]]		[[category:Lecture 2A High energy society]]
	[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: ~~Picking up~~ a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. ~~Picking it up~~ faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]		[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: Lifting a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. Lifting faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]
	<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>		<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>

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	[[Capacitor]]s often have a little bit of energy that can be discharged quite quickly. This short time means that they can have a fairly high power, even with a low amount of stored energy (this is useful with camera flashes, for example). [[battery\|Batteries]], on the other hand, contain much more energy than a capacitor but discharge that energy far more slowly, meaning that they have a lower power output.		[[Capacitor]]s often have a little bit of energy that can be discharged quite quickly. This short time means that they can have a fairly high power, even with a low amount of stored energy (this is useful with camera flashes, for example). [[battery\|Batteries]], on the other hand, contain much more energy than a capacitor but discharge that energy far more slowly, meaning that they have a lower power output.
	===An analogy with containers of water===		===An analogy with containers of water===
	[[File:Power vs energy.jpg\|300px\|thumbnail\|right\|Figure 2. ~~A representation of~~ energy vs. ~~power using~~ water ~~storage devices~~.<ref>(2014, June 30). ''What is the difference between power and energy?'' [Online]. Available: http://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php]]</ref>]]		[[File:Power vs energy.jpg\|300px\|thumbnail\|right\|Figure 2. The mug labelled 'Power' has a greater rate. The mug labelled 'Energy' has more water. This image represents how energy and power are different. Both have water and a flow rate.<ref>(2014, June 30). ''What is the difference between power and energy?'' [Online]. Available: http://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php]]</ref>]]

	Figure 2 shows a mug with a small amount of water being poured quickly and a jug holding a greater amount of water being poured more slowly. The mug is delivering more water in a given amount of time, but the total amount of water delivered will be less than the jug. The analogy is that the mug has higher power, but lower energy. The jug releases smaller amounts of liquid for a longer period of time. The analogy continues with the jug having a smaller power output but more energy. The mug releases all its water (energy) very quickly. Conversely, the jug holds much more water (energy), even if it is not losing it quickly.		Figure 2 shows a mug with a small amount of water being poured quickly and a jug holding a greater amount of water being poured more slowly. The mug is delivering more water in a given amount of time, but the total amount of water delivered will be less than the jug. The analogy is that the mug has higher power, but lower energy. The jug releases smaller amounts of liquid for a longer period of time. The analogy continues with the jug having a smaller power output but more energy. The mug releases all its water (energy) very quickly. Conversely, the jug holds much more water (energy), even if it is not losing it quickly.

Jmdonev: 1 revision imported

2018-09-03T22:23:36Z

1 revision imported

← Older revision	Revision as of 22:23, 3 September 2018
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energy>Jmdonev at 02:31, 13 August 2018

2018-08-13T02:31:36Z

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	[[Category:Done ~~2017~~-07-01]]		[[Category:Done 2018-08-03]]
	[[category:371 topics]]		[[category:371 topics]]
	[[category:Lecture 2A High energy society]]		[[category:Lecture 2A High energy society]]

	[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: Picking up a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. Picking it up faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]		[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: Picking up a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. Picking it up faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]
	<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>		<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>
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	===Engines vs. gas tanks===		===Engines vs. gas tanks===

	A car's engine determines how much power it can exert (this is a [[mechanical power]] often rated in [[horsepower]], as opposed to the [[thermal power]] which is how fast it burns gasoline), while the amount of [[gasoline]] in the gas tank determines how much energy the engine has at its disposal. The greater the amount of gasoline, the longer the engine can run without running out of energy. The more power the engine is using (like when driving fast or revving the engine to accelerate quickly), the shorter the amount of time the [[chemical energy]] available in the gasoline will last. Here's a page on tricks for [[improving fuel ~~efficiency~~]].		A car's engine determines how much power it can exert (this is a [[mechanical power]] often rated in [[horsepower]], as opposed to the [[thermal power]] which is how fast it burns gasoline), while the amount of [[gasoline]] in the gas tank determines how much energy the engine has at its disposal. The greater the amount of gasoline, the longer the engine can run without running out of energy. The more power the engine is using (like when driving fast or revving the engine to accelerate quickly), the shorter the amount of time the [[chemical energy]] available in the gasoline will last. Here's a page on tricks for [[improving fuel economy]].

	===Capacitors vs. batteries===		===Capacitors vs. batteries===

Jmdonev: 1 revision imported

2017-08-29T01:47:22Z

1 revision imported

← Older revision	Revision as of 01:47, 29 August 2017
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Jmdonev at 22:17, 16 August 2017

2017-08-16T22:17:18Z

← Older revision		Revision as of 22:17, 16 August 2017
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	[[Category:Done ~~2015~~-02-15]]		[[Category:Done 2017-07-01]]
	[[category:371 topics]]		[[category:371 topics]]
	[[category:Lecture 2A High energy society]]		[[category:Lecture 2A High energy society]]
	<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. ~~Even though they are used in everyday conversation as synonyms,~~ the ~~difference~~ is ~~subtle, but significant. This article aims to make clear~~ the ~~difference between power and~~ energy.</onlyinclude>
			[[File:lifting_a_box.jpg\|350px\|thumb\|right\|Figure 1: Picking up a box requires a specific amount of '''energy''', no matter how quickly the box is picked up. Picking it up faster will change the amount of '''power''' but not the amount of '''energy'''.<ref>This image is of a proper lifting technique from WebMd: http://www.webmd.com/back-pain/proper-lifting-technique Accessed, August 16th, 2017.</ref>]]
			<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Energy is the ability to cause change; power is the rate energy is moved, or used.</onlyinclude>

	==Energy==		==Energy==
	:''[[energy\|main article]]''		:''[[energy\|main article]]''
	Energy is ~~what creates~~ the ability to ~~push or pull through~~ a ~~distance. Its unit is the [[joule]]~~. Tasks require an amount of energy to complete. A [[battery]] will hold a ~~set~~ amount of energy; so will a given amount of [[fuel]].		Energy is the ability to create a change, for example, creating motion. Tasks (like lifting a box) require an amount of energy to complete. A [[battery]] will hold a particular amount of energy; so will a given amount of [[fuel]], like food.

			The base unit of energy is the [[joule]]. This means that a task, like lifting a box in figure 1, takes a certain number of joules regardless of how quickly the box is picked up.

	==Power==		==Power==
	:''[[power\|main article]]''		:''[[power\|main article]]''
	Power is how fast energy is used or transmitted - power is ~~a rate~~. Its unit is the [[watt]], which is one [[joule]] per [[second]] of energy used. A circular saw will draw a certain amount of power to run, and how quickly power is drawn from a battery determines how long its stored energy will last.		Power is how fast energy is used or transmitted - power is the amount of energy divided by the time it took to use the energy. Its unit is the [[watt]], which is one [[joule]] per [[second]] of energy used. A circular saw will draw a certain amount of power to run, and how quickly power is drawn from a battery determines how long its stored energy will last.

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

			:::* ''P'' is the average power output, measured in watts (W)
			:::* ''ΔE<sub>sys</sub>'' is the net change in [[energy]] of the system in joules (J) - also known as [[work]].
			:::* Δ''t'' is the duration - how long the energy use takes - measured in seconds (s)

	Multiplying a value of power and the period of time over which it is used gives an amount of '''energy'''. This is why a kilowatt is a unit of power but a [[kilowatt-hour]] (1 kilowatt times 1 hour) is a unit of energy.		Multiplying a value of power and the period of time over which it is used gives an amount of '''energy'''. This is why a kilowatt is a unit of power but a [[kilowatt-hour]] (1 kilowatt times 1 hour) is a unit of energy.

	~~===An analogy with containers of water===~~		Tasks (like lifting a box) take a certain amount of energy (a certain number of joules), but the faster the task is done (the smaller '''Δ''t'''''), the more power it takes (more watts).
	~~[[File:Power vs energy.jpg\|300px\|thumbnail\|right\|Figure 1. A representation of energy vs. power using water storage devices.<ref>~~(~~2014, June 30~~)~~. ''What is the difference between power and energy?'' [Online]. Available: http://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php]]</ref>]]~~

	~~Figure 1 shows a mug with~~ a ~~small~~ amount of ~~water being poured quickly and a jug holding~~ a ~~greater amount~~ of ~~water being poured more slowly. The mug is delivering more water in a given amount of time~~, but the ~~total amount of water delivered will be less than~~ the ~~jug. The analogy~~ is ~~that the mug has higher power, but lower energy. The jug releases smaller amounts of liquid for a longer period of time. The analogy continues with~~ the ~~jug having a~~ smaller ~~power output but more energy. The mug releases all its water (energy~~) ~~very quickly. Conversely~~, the ~~jug holds much~~ more ~~water~~ (~~energy~~)~~, even if it is not losing it quickly~~.

	===Engines vs. gas tanks===		===Engines vs. gas tanks===
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	[[Capacitor]]s often have a little bit of energy that can be discharged quite quickly. This short time means that they can have a fairly high power, even with a low amount of stored energy (this is useful with camera flashes, for example). [[battery\|Batteries]], on the other hand, contain much more energy than a capacitor but discharge that energy far more slowly, meaning that they have a lower power output.		[[Capacitor]]s often have a little bit of energy that can be discharged quite quickly. This short time means that they can have a fairly high power, even with a low amount of stored energy (this is useful with camera flashes, for example). [[battery\|Batteries]], on the other hand, contain much more energy than a capacitor but discharge that energy far more slowly, meaning that they have a lower power output.
			===An analogy with containers of water===
			[[File:Power vs energy.jpg\|300px\|thumbnail\|right\|Figure 2. A representation of energy vs. power using water storage devices.<ref>(2014, June 30). ''What is the difference between power and energy?'' [Online]. Available: http://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php]]</ref>]]

			Figure 2 shows a mug with a small amount of water being poured quickly and a jug holding a greater amount of water being poured more slowly. The mug is delivering more water in a given amount of time, but the total amount of water delivered will be less than the jug. The analogy is that the mug has higher power, but lower energy. The jug releases smaller amounts of liquid for a longer period of time. The analogy continues with the jug having a smaller power output but more energy. The mug releases all its water (energy) very quickly. Conversely, the jug holds much more water (energy), even if it is not losing it quickly.

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

J.williams: 1 revision imported

2015-08-26T21:30:43Z

1 revision imported

← Older revision	Revision as of 21:30, 26 August 2015
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J.williams at 22:44, 11 August 2015

2015-08-11T22:44:00Z

New page

[[Category:Done 2015-02-15]]
[[category:371 topics]]
[[category:Lecture 2A High energy society]]
<onlyinclude>'''[[Energy]]''' and '''[[power]]''' are closely related but are not the same physical quantity. Even though they are used in everyday conversation as synonyms, the difference is subtle, but significant. This article aims to make clear the difference between power and energy.</onlyinclude>

==Energy==
:''[[energy|main article]]''
Energy is what creates the ability to push or pull through a distance. Its unit is the [[joule]]. Tasks require an amount of energy to complete. A [[battery]] will hold a set amount of energy; so will a given amount of [[fuel]].

==Power==
:''[[power|main article]]''
Power is how fast energy is used or transmitted - power is a rate. Its unit is the [[watt]], which is one [[joule]] per [[second]] of energy used. A circular saw will draw a certain amount of power to run, and how quickly power is drawn from a battery determines how long its stored energy will last.

Multiplying a value of power and the period of time over which it is used gives an amount of '''energy'''. This is why a kilowatt is a unit of power but a [[kilowatt-hour]] (1 kilowatt times 1 hour) is a unit of energy.

===An analogy with containers of water===
[[File:Power vs energy.jpg|300px|thumbnail|right|Figure 1. A representation of energy vs. power using water storage devices.<ref>(2014, June 30). ''What is the difference between power and energy?'' [Online]. Available: http://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php]]</ref>]]

Figure 1 shows a mug with a small amount of water being poured quickly and a jug holding a greater amount of water being poured more slowly. The mug is delivering more water in a given amount of time, but the total amount of water delivered will be less than the jug. The analogy is that the mug has higher power, but lower energy. The jug releases smaller amounts of liquid for a longer period of time. The analogy continues with the jug having a smaller power output but more energy. The mug releases all its water (energy) very quickly. Conversely, the jug holds much more water (energy), even if it is not losing it quickly.

===Engines vs. gas tanks===

A car's engine determines how much power it can exert (this is a [[mechanical power]] often rated in [[horsepower]], as opposed to the [[thermal power]] which is how fast it burns gasoline), while the amount of [[gasoline]] in the gas tank determines how much energy the engine has at its disposal. The greater the amount of gasoline, the longer the engine can run without running out of energy. The more power the engine is using (like when driving fast or revving the engine to accelerate quickly), the shorter the amount of time the [[chemical energy]] available in the gasoline will last. Here's a page on tricks for [[improving fuel efficiency]].

===Capacitors vs. batteries===

[[Capacitor]]s often have a little bit of energy that can be discharged quite quickly. This short time means that they can have a fairly high power, even with a low amount of stored energy (this is useful with camera flashes, for example). [[battery|Batteries]], on the other hand, contain much more energy than a capacitor but discharge that energy far more slowly, meaning that they have a lower power output.

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