First law of thermodynamics / internal energy | Thermodynamics | Physics | Khan Academy

[@x0lamborghini0x]

He really understands the value of intuition when teaching hard to grasp concepts, that's why his material is the best. Cheers.

[@MrThe1234guy]

First law of thermodynamics- Never talk about thermodynamics.

[@coimbralaw]

👎🏻

[@iAnesxx]

is that a ******* ****** reference ?

[@janakm4135]

@@iAnesxxdefinitely 😂

[@eragon2121]

U for internal energy. The way I remember that is internal does not start with a U.

[@kdogallyall]

+eragon2121 I read this before I got to it in the video and was so confused

[@blackswan9645]

eragon2121 sodium starts with S but its NA in chemistry

[@red_isopat]

Black Swan its natrium in most languages

[@dhruvverma6938]

Neither does initial velocity start with u.

[@rajibhalder1991]

You are wrong, it's unternal energy.

[@rajharsh3114]

That Is like the first law of everything.

[@urairaktaifoi2190]

Raj Harsh คััา

[@munirasuappavu6437]

worse

[@kendo512]

I've been watching these videos for close to 4 years now. I love how you can tell the age of his videos by the resolution of the writing. The newer ones are so much more crisp.

[@wings4994]

And your comment was made 6 years ago..

[@kendo512]

@@wings4994 thanks for the flash back

[@kendo512]

@just some guy tired of life my friend I’ve had this KZbin account since 2007

[@MysticMD]

I cannot thank you more! You are simply amazing. A gift to the people who are eager to learn!

[@alexcourrier1918]

My favorite part: "U for internal energy... The way I remember this is because 'Internal' does not begin with 'U' " lol

[@aniswara480]

Dude you are some of the best professors out there you make mine look like a disappointment.

[@anuradhikabajaj9585]

@ aniswar lax 🤣🤣

[@jennyluvballet]

Khan, you're the best! Literally life saver for my exam in 3 days.

[@ivarbaratheon264]

My exam in 2 days lol

[@geico105]

My exam is tomorrow lol

[@RahulSharma-hk5yk]

My exam passed LoL.

[@ralphlaurenebol2835]

My exam is today

[@carlobadiola4994]

My exam is an hour away

[@ankidokolo]

When you realize, that you spent hours surfing the internet looking for this stuff explained, and they were here ALL THE TIME. Great courses.

[@VideoSouls]

8:00 internal energy

[@meldjibs]

@hybeerian I am a philosophy teacher in a school, and did this so my students could reply to your comment (we have been studying Ryle's 'myth of volitions'). You ask "can the energies of yore [sic] internal self exist in another form such as 'ghost' or spirit?" They have answered that question for you: that there is no such thing as an 'internal self' such as states of mind, they are in fact just ways of behaving, and thus physical like the 'carbon moleicles [sic]' that you recognise exist.

[@tonyc6163]

Khan post too many videos. Coolest people ever

[@hadiramzani3790]

The first part is law of Conservation of Energy...... Thermodynamics is about Heat in closed system. ΔU = Q - W could u pls tell more about the heat and adiabatic process.

[@ashasalelkar7457]

Adiabatic process is one where heat is neither transfered into or out of the system. Hence Q will be 0. Therefore W will be equal to -U. Now this is equal to -nCv(Ti-Tf). Cv is the specific heat at constant volume (Note - Cv is not only used for isochoric processes as it is thought to be by many. That is a mistake. Cv can be used for adiabatic and isothermal as well) . Now after substituting the expression for Cv. The FINAL eqn for W will be (PiVi-PfVf)/(gamma) - 1. So this just means that if work is done by a gas is positive, volume of the gas will increase and U will be more negative.

[@JennyCheng0102]

Be grateful that someone is willing to spend their time teaching you

[@라면먹고싶다-d5w]

Seriously, I wish my professor is like Sal. My professor is seriously terrible at explaining everything; I think he does not understand how a student learns.. Thanks Khan Academy.

[@shauryaverma2705]

Love you khan academy

[@NerdmasterChang]

@hybeerian While there may be many different ways to store or to release energy, energy itself is equivalent. The reason that static electricity doesn't kill you is that there isn't enough current (amount of charge passing a given point at any one second) while in an Alternating Current or Direct Current Circuit there can be if there is not enough resistance. This does not mean that the energy itself is any different though. You can also essentially break down all forms of energy into...

[@dracarys__xo509]

does this guy just know everything. no matter what class im struggling with, he's got something up his sleeve lol

[@nirunirmc3569]

Khan this is very useful ......

[@ShoxOhno]

Well i rather waste my time watching him write than to sit at lecture class staring at the ppt slides that confuse me. He's taking his time to help us students understand things that are unclear to us. Your comment was unnecessary and rude...

[@holligirl426]

I think Sal's favorite word is "intuitive" ;)

[@jfrieze78]

It can absolutely be applied to digestion. Calories are a unit of measure for heat. By determining the caloric intake, taking into account the efficiency of the human body in processing those calories, you can determine, fairly accurately, how much work the body would need to perform in order to "burn" the calories ingested.

[@9futbolstar]

This is so amazing...I cannot thank you enough KhanAcademy for all the helpful tutorials...It has expanded my knowledge in Chemistry and reduced my worries :) Thank You.

[@derrick8044]

7:32 KE was transferred to air particles (rub) = heat 11:49, 12:44 internal energy (U) - "all the energy that is in a system"

[@hamayun24]

Thanks .But I have a question.Are we serving as a system or as a surrounding ?

[@theartyard]

'And then I say no, Mister first law of Thermodynamics' XD 'The way I remember U stands for internal energy? Internal Energy doesn't start with a U!' Hahaha your funny comments in the vids help me to remember the content so much better !

[@jamz3553]

This is making alot of sense thanks you sal for your spend tim to save me from headaches at night😊

[@mehedihasan2294]

Love you sal Khan! You are the best teacher I ever had!

[@Viral_Shorts_News]

So the first law of thermal dynamics is that kinetic energy can change to potential energy and then convert back into kinetic energy mixed with some type of gravity effect 😊I got it thanks for explaining

[@jfrieze78]

Good question. The law of conservation of energy is precisely why perpetual motion is "impossible". For motion to be perpetual, there would need to be no negative forces acting on the object in motion. As he discusses in the video, friction is one of these negative forces. So, since the law of conservation of energy states that energy cannot be destroyed, it has to go somewhere, right? Well, in the case of friction, the energy is converted from kinetic energy to heat.

[@kaydodgy]

wow this was so easy to understand. If only one of my teachers came close to this.

[@JCROD5]

Awesome, good practice for remembering for a ME graduated some years ago!!!

[@socratus1]

Entropy Henry Poincare named the conception of "entropy " as a " surprising abstract " Lev Landau wrote: " A question about the physical basis of the entropy monotonous increasing law remains open " One physicist said : " The entropy is only a shadow of energy“ # History of Entropy 1 - Clausius : dS= dQ / T. 2 - Boltzmann : S= k log W 3 - Planck : h*f = kT logW # The formula of Entropy is : h*f = kT logW Israel Sadovnik Socratus

[@harvey2695]

This is Amazing

[@theabnationn]

I understand you better than my lecturer.. thanks so much khan academy

[@nathanclark2780]

So it was said that atoms don't really have rotational energy but molecules potentially do bc of sigma bonds that are able to rotate. However, atoms have atomic spin. Doesn't that translate into rotational energy? Was this an accidental omission or do atoms also have rotational energy? Much gratitude for your videos!

[@baretings1]

very very good guide, your not boring at all

[@rocknrollette666]

Personally, the writing helps; I watch videos where people just talk and it is not nearly as helpful as Khan. Plus, it creates the feeling of being in the classroom, which at the very least, gets me in the thinking mode that my house does not normally provide.

[@carolinemarwan911]

Thank you so much! Extremely helpful 👌🏻

[@IQ-rl2wx]

Khan Academy helped me so much in my development

[@wprandall2452]

If energy cannot be created, then it must have existed forever. But if it did, it would have to go back into the infinite beginning of time, which is not in reality. Time does not begin in a moment of time, but in infinity. What would be before it? No time, but no time doesn't continue, so time would replace no time. Only the abstract concepts, such as love, hate, math, geometry, truth, etc. exist there. If you tried to find their beginning, they would be there no matter how far you go back. Only at infinity would you find their source, but not energy; it is generated in a moment of time. Energy has to come from a created source in real time-space.

[@IAM-ku8vx]

How do you define time?Also does time exist at all?

[@IAM-ku8vx]

Time is a measure of change right?

[@gbonimabarmadia1482]

this is the coolest video i have ever seen....I love Khan Academy

[@redrodbert]

It’s always U = Q + W . The sign conventions of W differs depends whether ur class is chemistry, physics, or engineering.

[@sparkyin3d]

Best explanation ❤!

[@bonthavenkatajayanth7365]

When the ball is in motion the mass also changes. E=MCsquare Energy increased so to balance it mass shound increase as C which is speed of light in vacuum is constant.

[@The112Windows]

? Energy did not "increase".

[@ZnNlove]

U might be onto something, my balls increase in size to compensate for the increased energy while jiggling in a horizontal motion.

[@abelurbina2003]

Abel Ubina The WORK OUTPUT is more than double the WORK INPUT. So the theory of entropy is misconception. A 15 ball billiard pool to be strike by white mother ball When I computed the work done in pool (billiard) the white mother ball break the 15ball. F = 30lbs (White Mother Ball); D = 3ft (Distance from the white mother ball to the first ball to strike) SOLVE FOR WORK INPUT W = F X D; W = 30lbs x 3ft = 90Ft.lbs SOLVE FOR WORK OUTPUT First two ball extreme corner of the billiard ball 2 out of 15 ball W = F X D; W = 30lbs x 3ft = 90ft.lbs X 2ball = 180 ft. lbs The remaining ball (13pcs ball) can produce more than 90 ft.lbs The computation shows that the output work done is higher than the input work done Appreciated for your reply Thank you. Abel Urbina

[@brianoc10]

You're better than my physics lecturers ANY day

[@NerdmasterChang]

@hybeerian Thanks for your reply. My argument is essentially that the information in our brains is not energy. It is the result of patterns in our neural network. I will also stress that there is no such thing as one kind of energy or another kind of energy. All energy is equivalent. The energy inside my computer is exactly the same as the energy inside my head. The only difference is in the arrangement of that energy.

[@auroralevi2834]

In what order should i watch all of the thermodynamics content so i can understand the full concept

[@lovemorenkomo732]

Calculate AU for an endorthemic process in wc 20.6kj flows and where 13.7kj is done on the system

[@charisLUVSmj]

You are really AWESOME! thanks for being such a great help!!

[@zaireenzulaika5355]

thanks for this vid! it's really help me in the exams!

[@sakshiagarwal4821]

Thankyou so much sir you are just amazing.

[@NerdmasterChang]

@hybeerian Cont... potential and kinetic energy. These are different ways of storing energy, but that does not mean that the energy itself is different. "Fusion energy" as you stated, or the energy released by nuclear fusion is released from the mass defect of a nuclear reaction (a little mass is lost and a lot of energy is gained). "Thermal energy" or heat is the transference of kinetic energy from one substance to another. The energy is being stored in different ways, but it is all the same.

[@realdeal577]

What about General relativity with regard to ball falling? Technically, the ground(earth) is moving up.

[@smailwaltit38]

very few teachers uses this concrete method,,, talented

[@minamibayo07]

What is the significance of 13.375 in physics and the universe? Any insights?

[@NerdmasterChang]

@hybeerian Sorry for the long reply. A shadow is neither matter or energy, yet they clearly exist. Shadows contain information in that they paint a picture of the object blocking them. However, it would be incorrect to say that the information of the shadow exists as "energy". The previous analogy of the paper can be applied to patterns that your neurons make in your brain. I would say that there is information there, but the energy present in the cells is not it.

[@plaxen1]

thank you!

[@jfrieze78]

And, when the energy is converted from kinetic to heat, the object decelerates. The only way an object could move perpetually would be if the object was in an "ideal" system void of any forces outside of the object's system.

[@ChirtyPoundsOfBoost]

@kroflet There is, the ball is trasnferring its kinetic energy into thermal energy when its traveling against gravity as well. He made it seem like the force that accelerated the ball upwards was much greater then when the force of gravity acceled it downwards.

[@sethuhlophe3983]

If energy or matter cannot be created nor destroyed can you explain quantum fluctuations where particles pop in and out of existence and completely obliterate each other? I’m new to this topic

[@crystalbramhill5277]

If you had a tool to help you learn and be successful/pass thermo, what would you need in the tool? What issues/challenges did you experience taking thermo? What do you do when you are "stuck" and how do you get unstuck? If you have disabilities, what are accessibility needs to utilize an online tool? Why is thermo a difficult coarse?

[@pangasinanstinglessbee]

Nice presentation! BUT, isn't that air resistance was always present when you threw the ball up and when the ball was falling down? A constant is present in opposite directions (meaning the factor of air resistance is cancelled out), so that the velocity going up should be the same as when going down.

[@swb6843]

Whats the difference between work done and pressure volume work?

[@DrGregoryHouse100]

Right after watching this i went outside and threw a rock in the air XD

[@anjxr82]

i have question: A glass cleaned in 45celcius hot water and placed on the table bottom up. The room air at 20 celcius that was trapped in theglass gets heated up to 40 celcius and some of it leaks out so the net resulting pressure inside is 2 kPa above ambient pressure of 101kPa. Now the glass and the air inside cools down to room temperature. what is the pressure inside the glass?

[@Willxdiana]

wow physics on chemistry! this helps since Im takng physics 1 with chem 2.

[@Dyslexic-Artist-Theory-on-Time]

Very well explained!!

[@DanEMO592]

Yea. You can watch the videos at 2x the speed like I do! :D It saves so much time when I am watching lectures or learning things on youtube!

[@breakdancer100]

The third law of thermodynamics is that if some yells "stop" or goes limp, taps out, the fight is over

[@kroflet]

@ChirtyPoundsOfBoost Thanks! So the air resistance when the ball is being thrown upwards is much smaller than AR when the ball is moving back to the ground? Therefore, it's not "worth" mentioning the upward resistance?

[@saeedkhanazam]

very clear , well done

[@IftekharSa]

this was really helpful

[@Regnorok]

Wouldn't throwing the ball up meet the same amount of air resistance as it would when falling? Thus making the speed of the ball the same both ways?

[@ChirtyPoundsOfBoost]

@kroflet No the air resistance is the same, the density of air in this frame of reference is the same.

[@smailwaltit38]

thank you for this interesting video

[@OCPRS]

Does the First Law of Thermodynamics apply to cold and heat energy or does it extend into types of energy like electricity (or even bio-electric -neurons) for example? If anyone can help me with this curiosity please send me a reply. Thank you.

[@jrro0t]

technically energy can be created or destroyed, for example, if matter interacts with the correct amount of positron or "anitimatter", it creates a huge amount of energy.

[@abelurbina2003]

Hello Sir, When I computed the work done in pool (billiard) the white mother ball break the 15ball. The work brought OUT is more than the work brought IN. Let’s try to compute. F = 30lbs (White Mother Ball); D = 3ft (From the white mother ball to the first ball to strike) SOLVE FOR ENERGY IN W = F X D; W = 30lbs x 3ft = @t. ENERGY IN SOLVE FOR ENERGY OUT First two ball extreme corner of the billiard ball 2 out of 15 ball W = F X D; W = 30lbs x 3ft = @t X 2ball = @t. The remaining ball (13pcs ball) can produce more than @t. The computation shows that the output work done is higher than the input work done so the theory of conservation of energy is misconception. Appreciated for your reply Thank you. Abel Urbina

[@vishwaskishan]

I also liked this one..and also apreciate the person who upload these kind of helpful videos... carry on... God Bless you!!

[@randygeen5621]

So of energy can't be created or destroyed. How is it possible that subatomic particals can be created in a vacuum, even though it is for a milisecond or less?

[@somebassdude]

I have a question. Why do you use the capital delta in U = q + w, where q = -w ? Doesn't q and w depend on how you got them? And therefore they aren't situational functions, but path functions? I don't know how you call these functions in english though. In Dutch they're called 'baanfuncties' and 'toestandsfuncties'

[@antonytolstunov7513]

Incredibly helpfull

[@m92singh]

I prefer the step by step actually, sticking on a whole lot of information on the screen can make the student confused and then not know how to follow the information.

[@masterrace921]

So as energy is passed around from thing to thing it loses energy by transfer to other particles Sorta like if you got hit by a football it would hurt like hell But if bounced off you and hit your buddy it would hurt a lot less as the ball lost so much energy hitting you that the velocity was drastically slowed.

[@Слободан.Раденик]

Thank you for this video,it help me a lot.Greetengs from Serbia

[@sabariahsiraj8804]

you are the best teacher

[@SpaceTrooper50]

Possible in Earth because kinetic energy can be use to "defy gravity" in order to gain potential energy. But a giant Wheel bigger than a Ferris Wheel is needed to make it happen. All it needs is the propulsion which will be the ball and a propulsion driver.

[@asimrashid5614]

from where kinetic comes from ?although the participial is at ground state the is no motion. kinetic energy is due to the motion of particles /mass??

[@BryceSH1992]

wow. Its week tw and im still confused but now i understand. Thanks very much

[@SuperSuadad]

Thank you khan, you are the man!

[@sameerncce]

great video....thank you so much god bless u.

[@rogerg4916]

Is the amount of energy that goes into the production of a hydrogen bomb equal to the amount of energy released when the bomb is detonated?

[@magmasceptre]

That's why i like his channel!

[@pandaaa_bear]

So in the case flash paper, if one burns the paper it just disappear . So what has been done to the energy not destroyed????

[@عليخلفطاهر]

Thanks 😌

[@fuckkokoo]

mind blowing explanation of U= Q plus or minus W

[@EclipZeMuzik]

dude you're amazing i love this!