it's the perfect way to explain it i've been skippin phy lectures and watchin vids instead cuz when i watch these vids i understand the subject well and the best of all i don't fall asleep
@ 8:23 The only thing we get is a formula telling us how to calculate the pressure P when N particles hit ONE SIDE OF THE BOX at the same time. What about the pressure on the other walls??? @ 11:07 Only 1/3N particles are hitting that ONE WALL !!!
so here i am watching this khan's video instead of listening to my lecturer. Tbh its easier to learn here than to learn from my professor and it took me less than 15 minutes to figure out things than listening to my professor for 2 hours session. SO WHY AM I PAYING MY COLLEGE TUITION FEES FOR :((((((
For those who don't get why we took time interval instead of Collison time ans what it tells us . Well it gives us magnitude of force as if a force acted on particle as it went from one wall to another wall and back.
is temperature related to the only translatory motion of the gas molecules or also to rotatory and vibratory motion? if so why do we only consider the change in the linear momentum in the discussion?
Yeah actually for real gases you have to consider that as well. But for ideal we neglect all intermolecular force and gravitational force so particles always move in a straight line path (called free path). They change directions only when they collide with other particles but after colliding they again travel in straight line path. So you don't need to calculate any other momentum other than linear momentum for ideal gases
Something didn't make sense to me. when we talk about change in momentum isn't delta t the time spent in the collision itself why would we use the time between two different collisions?
Question, How come we use delta P = 2 mVx , and the V here is for velocity then you used v= x/t where V here stands for speed not velocity and took its valuue to plug it in the delta P = 2 mvx . explanation please?
I have a doubt if we assume that total p particles are there and then we say n number of particles collide in the right plane in x directionand say some x particles collide in the upper plane in y direction then how is the mean velocity is same ux= uy=uz
Can some one answer me the air density is less in higher altitude that of lower altitude meanings , gas molecules due to effect of gravity have more density and form lower layer of atmosphere in more amount. It is against one of the postulates of KTOG of is the assumption wrong!?
god i wish my book can highlight the fact that we are interested on wall A only in the beginning , for the whole hour i was thinking why the fuck only x-component......
+Ankit Kumar Great question. It's a fine point, but he adds all the particles at the same time because if you remember when he was replacing delta t, he stated that delta t was the time interval for a particle to collide with the wall, bounce off the parallel wall on the other side, and then come all the way back. That means every particle will eventually collide with the wall during that time interval. There are alternative derivations where you leave delta t and apply it to the number of molecules moving rightward at a given time, in which case you do divide by one half (because half are moving rightward the other half are moving leftward), which is what you were probably thinking to do. That method is also completely fine and you arrive at the same answer. I prefer that method because you don't have to arbitrarily multiply by one half to see the kinetic energy term. It's there from the beginning. :)
This explanaition is wrong !!! You can't use the momentan force applyed on the wall like it will be with F= ∆p /∆ t , but you need the average Force applyed on ONE WALL (always the same). So you have to calculate the total momentum over the time (F_average=p_tot / time_tot) and to dothat , you make a sum over all the momentum diveded by the sum of all times. => F_average = (-2 p_x (t_contact ) + 0 (t_travel)) / (t_contact + t_travel) = (-2 p_{x} (t_contact ) / (t_contact + t_travel) , the 0 is the momentum aplied on the wall for time that particle is away from the wall (t_travel ). since t_travel >>>>>>> t_contact YOU GET F_average_ = (-2 p_{x} (t_contact ) / (t_travel) This detail is very important for the logical construction of the solution , otherwise you learn wrong concepts.
You did a better gob at explaining this in 15 minutes than my professor in 3 weeks. Thank you!
same here!
Same for me !
My teacher tried it in 15 minutes as well and that did not work out
3weeks?????? My professor kust gabe us random worksheets lmao. no discussions
My private teacher in 13.5 mins
The best explaination that I've found over the web, thanks!
You're an excellent teacher David!
its been 7 freaking years and this is still helpful, thanks man.
This is quite literally one the best Physics videos out there. Gave me goosebumps learning about this :)
it's the perfect way to explain it
i've been skippin phy lectures and watchin vids instead
cuz when i watch these vids i understand the subject well and the best of all i don't fall asleep
@ 8:23 The only thing we get is a formula telling us how to calculate the pressure P when N particles hit ONE SIDE OF THE BOX at the same time. What about the pressure on the other walls??? @ 11:07 Only 1/3N particles are hitting that ONE WALL !!!
so here i am watching this khan's video instead of listening to my lecturer.
Tbh its easier to learn here than to learn from my professor and it took me less than 15 minutes to figure out things than listening to my professor for 2 hours session.
SO WHY AM I PAYING MY COLLEGE TUITION FEES FOR :((((((
anonymous - same here
Just went to a lecture and didnt understand most of this stuff, watched two Khan academy videos and everything is so clear to me now. Thanks you!!!
"It's so important I'm gonna write it again"
-David SantoPietro, 2014
delta t should be the time taken for the change in velocity bw the collision on the surface of wall
my doubt
Same here.
I was so distracted by the cube doing the weird optical illusion thing
Yeah , same.
I hate you. I can't unsee it now.
Oh god... I wasted more than 7 days on this topic none couldn't explain it . At last i got it. Thank you 😍
Why isn't this up on the website with the ideal gas equation series?
I wish I saw this before today. Thank you very much for making me understand this.
OMG! That was a great explaination (especially for the last part)
You are a life saver dude...
Love from India ❤️
i've been relying on CZcams explanations for my finals lol Khan Academy did a stellar job at explaining every single subject. propsssss.
thank you so much for your kind and sophisticated explanation !
Thankyou sir, you helped me understand that why aren't we taking the delta t as the time of impact,, God Bless you
that is exactly what i was looking for.Thanks for great explanation
wow !! really appreciate it ! .. such an awesome explanation!!
The mentioning of the link between macroscopic and microscopic quantities is great!
Thanks for your video! Seriously helped a lot.
Simply amazing! I understand it a lot better now, the use of colours really helped too :)
Ohhhh
thx for making understand the 1/3 in this formula which my professor just wanted me to memorize mechanically
For those who don't get why we took time interval instead of Collison time ans what it tells us . Well it gives us magnitude of force as if a force acted on particle as it went from one wall to another wall and back.
Thank you so much for your excellent explanation!!
Calculation of the pressure of an ideal gas...! It's in HC verma.. but this video makes it even more easy to follow! 😊
is temperature related to the only translatory motion of the gas molecules or also to rotatory and vibratory motion? if so why do we only consider the change in the linear momentum in the discussion?
Yeah actually for real gases you have to consider that as well. But for ideal we neglect all intermolecular force and gravitational force so particles always move in a straight line path (called free path).
They change directions only when they collide with other particles but after colliding they again travel in straight line path. So you don't need to calculate any other momentum other than linear momentum for ideal gases
I loved this video. You explained it so well and made me pretty excited about doing some maths in the process! Nice work :)
Man, you are amazing! Thank you!
Can you please also make a video explaining the derivation in the first chapter of Max Born's Atomic Physics for same equation?
Very clear for me understand
These very helpful
Are you assuming that all particles are traveling in a straight line from one end of the container to the other by using 2L as the distance?
good explanation as always
Thx khan academy
Very clear presentation.
this is fantastic, really love it
really helpful
THANK YOU
great explanation i love it.
Thank you 😊
Great explanation.good job 👍🔥🔥🔥
amazing explanation David
Superb video
Thanks for clearing bdoubt
Thanks man, like always.
It was really very good and helpful.
Something didn't make sense to me. when we talk about change in momentum isn't delta t the time spent in the collision itself why would we use the time between two different collisions?
It was so much fun to learn it
Is this on Khan Academy Website?
excellent presentation. Does anyone know of any molecular theory of gases books?
Very nice and interesting presentation.
Thank You !
Thank you thank you thank you!👍👍👍👍👍👍
thank you khanacademy
I still don't get the reason given at 4:15
The explanation made me like and share he video
Question, How come we use delta P = 2 mVx , and the V here is for velocity then you used v= x/t where V here stands for speed not velocity and took its valuue to plug it in the delta P = 2 mvx . explanation please?
I AM GOING TO HAVE A PHYSICS EXAM IN THE COMING WEDNESDAY. THIS VIDEO IS REALLY AMAZING! THANK YOU SO MUCH BRO!
It was 5 years ago 😃i just wonder what your career is now or what you are doing
u are amazing mate
How do you work out Vx2 average.
There r 10 concepts of KMT of gases right? could u explain those individually?
thanks
I have a doubt if we assume that total p particles are there and then we say n number of particles collide in the right plane in x directionand say some x particles collide in the upper plane in y direction then how is the mean velocity is same ux= uy=uz
God bless you :)
Sincere thanks. You made my day. Concepts cant be cleared any better :-)
Hlo
good presentation
Wallahi you are awesome :D
I become your fan. So nice... 😇
excellent boss
I don't understand why velocity in this lesson equal to distance over time please anyone answer ? And why did the displacement equal to 2L?
It's too simple my teacher was explaining this in a quite complicated way that I just.....dozed off😴😴😴😝😝
thanks a lot bro you just saved me from failing
It will take longer then 2l as there are intermolecular collisions also increasing time
Thanx
please someone let me know the difference of Energy of Electron kT between molcule E=3/2kT
Nice❤️.
ty sir
Can some one answer me
the air density is less in higher altitude that of lower altitude meanings , gas molecules due to effect of gravity have more density and form lower layer of atmosphere in more amount. It is against one of the postulates of KTOG of is the assumption wrong!?
you racists fker
does anyone knows what app is he using here?
You're my best
Algebra God!!!
Wow amazing explanation you made it look really easy....
+jaideep sohal Seriously. What I love is how he says how awesome each equation is and then explains what they're supposed to mean.
why do your pic have the MIDDLE FINGER :(
There are two fingers lol... It doesn't have just middle finger
I like this guy
just a curious question what are u using to write because it looks like handwriting but I can see the cursor?
Smoothdraw 4
hiiiican you tell me please what ddi you use to make this video what is that tool you use to appear on screen like a black board???
+Mohammed haggag Sal uses SmoothDraw v2.1
+manuveer singh and movtavi, and microsoft paint, and... yea
Like it
Please explain why Velocity in x,y,z directions are equal.
Since the gas is isotropic...(having same proper ties in all directions)
Ideal gas with:
P=10^5Pa
V=2 l
What is the average kinetic energy of translational motion of the molecules of this gas?
Mihai Mi Either number of molecules of gas or number of moles of gas is required to solve it.
god i wish my book can highlight the fact that we are interested on wall A only in the beginning , for the whole hour i was thinking why the fuck only x-component......
TheSunshineRequiem ure not alone friend.. ure not alone:)
I did fifteen pushups for you
💜
❤❤❤
@Hamza Shaukat Khan Acadamy is just an organization.
why it is two l?
Why is N not divided by 2 as well?
why are we adding all N molecule forces at a same time because all the molecules of gases cant hit the face at same time please answer
+Ankit Kumar Great question. It's a fine point, but he adds all the particles at the same time because if you remember when he was replacing delta t, he stated that delta t was the time interval for a particle to collide with the wall, bounce off the parallel wall on the other side, and then come all the way back. That means every particle will eventually collide with the wall during that time interval.
There are alternative derivations where you leave delta t and apply it to the number of molecules moving rightward at a given time, in which case you do divide by one half (because half are moving rightward the other half are moving leftward), which is what you were probably thinking to do. That method is also completely fine and you arrive at the same answer. I prefer that method because you don't have to arbitrarily multiply by one half to see the kinetic energy term. It's there from the beginning. :)
This explanaition is wrong !!! You can't use the momentan force applyed on the wall like it will be with F= ∆p /∆ t , but you need the average Force applyed on ONE WALL (always the same).
So you have to calculate the total momentum over the time (F_average=p_tot / time_tot) and to dothat , you make a sum over all the momentum diveded by the sum of all times.
=> F_average = (-2 p_x (t_contact ) + 0 (t_travel)) / (t_contact + t_travel) = (-2 p_{x} (t_contact ) / (t_contact + t_travel) , the 0 is the momentum aplied on the wall for time that particle is away from the wall (t_travel ).
since t_travel >>>>>>> t_contact YOU GET F_average_ = (-2 p_{x} (t_contact ) / (t_travel)
This detail is very important for the logical construction of the solution , otherwise you learn wrong concepts.
thank you
thank you, you cleared my confusion
Man you killed the shit outta the topic.
SO confusing. about to just keep watching it till it clicks ☺