Carnot cycle and Carnot engine | Thermodynamics | Physics | Khan Academy

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Introduction to the Carnot cycle and Carnot heat engine. Created by Sal Khan.
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[@ninjabomberboy]

Haven't started watching this explanation yet, but I already know its going to be a shitload better then my lecturers

[@TurdFurgeson571]

Don't discount the fact that by now you're hearing this information for at least the second time. Try doing things the other way next time. Watch Khan first, then go to lecture. I promise you will enjoy lecture more than you do now. You will be prepared to work with this information on a new level in class and you will likely be able to ask better questions, which will only help you understand this stuff. Perhaps that may be the source of your trouble, too, that you don't ask questions. I don't know you, but I do know that most students remain quiet and confused, and thus frustrated at their professors or the content. It seems like most don't want to look stupid in front of peers. It's okay to look stupid when learning things you've never learned before. (You're all stupid! Why wouldn't you be? You've never done this before.) Regardless of the expectations you have for yourself, I promise you your instructor is not expecting you to completely understand this stuff after hearing it _one_ time. No one expects that. For the love of who or whatever you believe in, ask questions. If you're afraid to speak up in class, send an email, go to office hours, hell do your homework at office hours. "That's so awkward!" Oh well. This is why you pay tuition, not to sit in a class and hear something once, but to actually learn the material; learning requires this work on your part though, it's an active process. That's how to use your professors, and get the most out of a mortgage's worth of student loans you're going to have. Khan is great, but realize that you had to take time out of your day to participate in your learning. Your professor and Khan are both available, but it's up to you to actually utilize the resource.

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I was 8 xD

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Paagal

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but I feel why do I pay even to college?

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For that piece of paper called a degree

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You are so much better than my thermo professor....

[@TET2005]

Thank you sir. Your video is worth a million dollar instead of reading the boring physical textbook. As long the concepts are grasp properly, it will stay with you forever.

[@ahobimo732]

Such a great explanation. I'd forgotten just how incredible Khan Academy was.

[@arjuncalidas2736]

10:13 I think as pressure is decreased, the volume is increased. You said volume goes down. But awesome work here.

[@jamiegollings]

Fell much more comfortable about my Therm exam on Monday now, thanks!

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Haaa if i had access to internet when i was a student....

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Janmay Patel lol :P i had forgotten about this

[@taltheking100]

Thank you for the video! You made it all so simple to understand

[@sergiolozavillarroel3784]

8:43 "I should be talking about thermodinamics not drawing" lol

[@Quran722.]

Simply made too simple by khan

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[@mikeb5174]

also, at 7:00 : im taking pchem I right now, and we do define deltaU=q+w. so qab=-wab.

[@KVI3I]

One Question: By removing the Rocks, you have to use Work from the outside - would'nt that make the process irreversible?

[@Vasu-qn6kj]

Wouldn't that also make it redundant? I mean Carnot cycle is utilised in an engine right.. you made an engine because you wanted to do work on something.. but if you have to do some outside work to make that happen.. then you're basically doing work to get work. Doesn't make sense to me. But ofcourse I'm obviously missing something. I just don't know what that is.

[@phantomj8449]

They were actually adapted from the rotation of a train wheel, when as the rocks decrease, it indicates the axes start to have less push on the wheel (or backward resistance), closing in on 90 degrees to the forward motion of the train. Keep on going, and the wheel’s spin pushes the piston in the opposite direction, compressing the gas and then there’s the next 2 stages, completing the cycle.

[@themeharsingh]

Why temperature should goes down in 1 st and 2nd step if pressure is decreased and volume incresed ( if reservoir wasn't there)

[@s0m0c]

in both process the volume is changing going up during expansions and going down in a compresion

[@mikeandino81]

So A to B is adiabatic and so is B to C? I'm sorry but isn't T2 going into the system? Or is this a system definition issue? Thanks for the video, though. Very good!

[@s0m0c]

adiabatic process means isolated, so no heat transfer can ocurr,the system travels trough an isoterm and if the temperature doesn`t change for our system, neither do the Internal energy is going to change, so is constant. But in and adiabatic process the temperature of the system is not constant is not travelling along the isoterm anymore.

[@internationalgolfconstruction]

Can we say that the work done to the system from A to C is equal to mgh of the stones where h is the distance traveled by the piston?

[@ptcala99]

shitty microsoft paint-esque program + 20 minutes = lucid explanation of the Carnot cycle....amazing!!! Thank you so much!!! I feel more comfortable with thermo than ever!

[@s0m0c]

at 10:11 Salman Could have meaned "my pressure would have kept going down and my volume would have kept going up"

[@avestak]

Hi, Love your videos, is there a way to watch just thermodynamics ones? Thank you

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ı wish ı could like it for billion times hahhah

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Thank you so much for your helpful tutorial! :D

[@clementkoshy5438]

If the internal energy of the ideal gas from 1-2 was zero ( the work done (1-2) was to increase the volume and decrease the pressure ) , then what is the internal energy of the ideal gas during adiabatic expansion ( process 2-3 )

[@jeanbernard3469]

Thank you dear!

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He sounds like Tom Hanks at 1.25x speed lol

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Yeah lol

[@doganguler1]

there is no reservoir from D to A as no heat is exchanged in a adiabatic process.

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TYSM 🥰

[@ramansb1213]

i don't understand how is it adiabatic if the tempratures system goes from T1 to T2?

[@aabidmushtaq3243]

because reservoir is removed also pressure is decreased by removing pebbles

[@chhavishree1359]

Thank you so much

[@alfredjackson1620]

i need to ask how does this not violate the law of conservation of energy. Basically a piston can produce more energy than it needs to reset. So since the compression only requires a bit of work and the expansion produces more work we have a perpetual motion piston.

[@pandaman9690]

Well, I don’t think this violates the conservation of energy because the pebbles being removed and added is work coming from the environment. Also, the reservoirs are in practice not infinite, so eventually, it will equilibrate.

[@vijgenboom2843]

Thank you ❤️

[@draegernaut]

THANK YOU, i understand now

[@nikhilkamichetty739]

the sound of crows cawing in the background at around 8:45!!!

[@nurazom1556]

if heat is the transfer of kinetic energy then why heat is constant in adiabatic process??

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its awesome i can learn phy very easily

[@Anujsingh-mo1vd]

Where does the net amount of work done by the system went in carnot cycle, from the law of conservation of energy.

[@sgsg5903]

Very good thanks Very much!!

[@kinzaarif8053]

Great explanation!!keep it up

[@BANKO007]

Why does the gas continue to expand during the adiabatic expansion after the isothermic expansion? What determines when the heat should be removed? Heat can be turned into mechanical energy without the adiabatic elements. Something is missing. "Remove some rocks" doesn't explain anything.

[@phantomj8449]

Because the rocks are being removed. You are right in a slow reversible process, the weight of the rocks should only be marginally lighter than the gas pressure under reversible heating, and as soon as heating stops, expansion should stop. They were actually adapted from the rotation of a train wheel, when as the rocks decrease, it indicates the axes start to have less push on the wheel (or backward resistance), closing in on 90 degrees to the forward motion of the train. Keep on going, and the wheel’s spin pushes the piston in the opposite direction, compressing the gas and then there’s the next 2 stages, completing the cycle.

[@Anujsingh-mo1vd]

I understand. Work done went

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first 2 mins ----> instant subscribe

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thAnks

[@SvSzYT]

isnt the most of the work done during the adiabatic processes?

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Do you use the mouse or a tablet? love your work! so awesome!

[@vibhukumarsubramani1939]

of course tablet

[@theincapable]

@TheMIkex24 He accidentally took the wrong word. The pressure is going down and the volume is going up, as you can can see in the figure.

[@shootshoot]

man you're really cranking these out, it's hard to keep up

[@arjundenath8535]

11 years, How those videos affected you?

[@Growriginator]

Thank's from Germany!

[@erakashyap1110]

I can’t thank you enough :)

[@seonghwang6059]

How does removing a reservoir from B to C decrease the temperature? Sorry for stupid question.

[@sheenak.r9860]

seong hwang Because pressure is directly proportional to temperature.So when pressure decreases temperature also will decrease.

[@phantomj8449]

Expanding gas at a pressure does work on the environment, it loses internal energy, and this energy is only determined by temperature, so temperature decreases.

[@DMZ509]

you need to watch the previous vids, you can't understand a subject without knowing the sub-subjects, especially in chemistry

[@hazarbodur19]

why heat doesnt change?

[@Adaeze611]

In the future I will name by daughter adia and my son batic since we did it in isolation and energy was lost in their formation

[@lalox3003]

THANK YOU SO MUCH!!!!

[@meenakshi_srinivasan]

How is it work done by the system....??????? Is the piston raising because of the heat from the reservoir, no right its raising because we remove the stones... Then how is it wd By THE SYSTEM

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How do you write so well with a cursor?

[@Gloin79]

he's probably using a elektronic drawing board

[@serinmarypr7198]

thanks a lot

[@izzyAKAisra]

why there cannot be a system that is describe by a circle instead of rectangle?

[@sauravchakraborty2654]

The system is described by four hyperbolas. There cannot be continuous increase or decrease of work done as in a circle.

[@thispageismylife]

too bad my tasks are at a complete different level of difficulty

[@agent-sz2qj]

can anybody explain to me why the amount of heat added to the system is bigger than the amount of heat that leaved the system ?

[@allawliet4564]

the silence breaker because some of heat is used in work....

[@chayanka_kaushik]

Left*

[@reasoningteachingbybeautyr6716]

👌👌explaination

[@johnkelly3886]

Thermodynamics gives bounds on real engines. Moreover, the explosion of the fuel mixture is not even approximately reversible. How can thermodynamics be of any use in designing real world internal combustion engines?

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That's why they called 5 more... :)

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thermodynamics is part of chem

[@ahmedkhalidkmd]

why is the isothermal curve steeper than the adiabiatic curve ???

[@wouterinho7]

it's not

[@zeeshanmuhammed8883]

you mean less steeper ?

[@wouterinho7]

The adiabatic curve is much steeper than the isotherm. When you look at the equation for an adiabatic curve PV^gamma=const, you can directly observe this.

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the video is so messy.

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You're animations are just fine man.. I've never taken formal physics courses, but for 10+ years now I've done my own research via books,magazines etc... Your videos by far are the most clear and to the point..your analogies are tough sometimes..but het..that's what pause and repay are for! Keep it up brotha! This is much appreciated!!

[@khletus9061]

10 more years have passed since your comment, how is your research going ?

[@Growriginator]

Thank's from Germany!

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Thx a lot

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I want to know what drugs carnot was doing, they seem pretty good!

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Lmfao

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Existential crisis.

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Teach forever sir

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The day after tomorrow is my physics exam. While revising thermodynamics , i was facing some difficulties to understand this topic. Thanks to Sal for explaining the concept in a easy way. Love from Bangladesh❤️❤️

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I tripped on your shit. I understood it all. thanks.

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all lectures deliverd by this HONOURABLE professor are soooooooooo nice. i like all the lectures and enjoyed. i realy appreciate wow. keep it up sir. May God give u long life to educate us

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I can't thank you enough!!! SAL!!! MA MAN!!!! seriously, I was really troubled by this... I'm so grateful that youtube exists and there's a channel called khan academy

[@SabbirAhmed-nw2cv]

I was struggling to understand this. Thank you for this!

[@rubaiyattasnim1297]

For some reason I kept getting confused about how Q1 was coming into the system and Q2 was going out. This video helped so much!

[@jdfab_ulous]

From B to C (adiabatic) process, why does Volume keep increasing since there's no change in heat transfer and there's no source / reservoir?

[@arnatri1503]

Fabrice Vieillesse when adiabatic expansion is taking place, the piston is just allowed move out. Therefore the gas expands increasing the volume.

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I used to think my life was full of problems. Then I found this comment section

[@mohiuddinkhan4069]

from 2021

[@Gahstupidcomments]

chemistry textbooks u = q + w physics textbooks u = q - w chemistry defines w as work done on the system physics defines w as work done by the system same equation MIND YOUR SIGNS

[@ojasthakurx]

you have got a nice voice and understanding but use better animations the current one suck

[@iknownothing35]

Shouldn't delta-U have a specific value considering for an adiabatic process Q = 0 always? In that example, W(AB) = 0; no work has been done. But the gas did do work considering the change in Volume... idk maybe I'm not seeing it.

[@glimpseofanpilgrimage5323]

hey why the slop in the graph is more steaper at BC

[@M_0892]

Thanx so much!

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[@liaoyuqian4172]

It’s kinda crazy when I fully understood the mechanism behind it. It gave me that”aha!” moment. Again, I am thoroughly impressed by Khan academy

[@CreQ]

Our internal energy did not change? I thought pressure was kinetic energy, and if the pressure went down the internal kinetic energy went down? Just like if you removed pressure from a Co2 cartridge by firing a pellet gun, the internal energy changes and each successive pellet will fire at a slower velocity.

[@amritbasavaraj9146]

But how does this cycle interact with Kevin-Planck's statement that any system cannot absorb heat from a reservoir at a fixed temperature and convert it wholly into work?

[@mcgregor107]

Dude, this is an iso-thermal expansion, not adiabatic. No heat flow and a change in temperature for adiabatic, no temperature change (and heat flow required to compensate) for isothermal.