Molecular Kinetic Theory (simple derivation)

Molecular Kinetic Theory (simple derivation) - Kinetic Theory (Lesson 4)

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3 жыл бұрын

Lesson 4
The kinetic theory of gas allows us to derive the equation of gas pressure pV=1/3 Nmu^2.
In this video, we look at what the root mean square speed is and how that is used in the gas pressure equation.
Lesson 3
Two versions of the empirical ideal gas equation:
pV = nRT
pV = NkT
• The Empirical Ideal Ga...
Lesson 2
Boyle's law, Charles' law, and Gay-Lussac's law, and the combined gas law
• Boyle's Law, Charles' ...
Lesson 1
Describing an Ideal Gas - Moles, Molar Mass, Relative Molar Mass, Avogadro Constant
• Describing An Ideal Ga...
#physics #kinetictheory #alevelphysics #neetphysics #class11
Music credit:
Song: Dipcrusher - Islands (Vlog No Copyright Music)
Music provided by Vlog No Copyright Music.
Video Link: • Dipcrusher - Islands (...

Пікірлер: 73

@lionelcoleman8888 3 жыл бұрын

I am a fellow Physics teacher and now a huge fan of you and your channel! Beautifully pitched at GCSE and A level students - succinct and lucid. Thank you so much for all of your efforts and generosity. I am in awe.

@vt.physics 3 жыл бұрын

Thanks, Lionel! Very kind of you!

@midnightstorm4290 2 жыл бұрын

Thank you so much! This was very clear and simple to follow so keep posting more!

@sanketpathak6621 2 жыл бұрын

Explained in a very simple way, thanks!

@starman3533 2 жыл бұрын

thanks a bunch, clear and precise explanation

@RounakDagar 2 жыл бұрын

Amazing clear explanation Loved it

@jizzyjjarold150 Жыл бұрын

Hold on. But isn't delta t the duration when the particle is colliding with the wall and experiencing the net force? After all, force = the change in momentum over the change in time. And the change of momentum happened only when the particle collides against the wall to experience a net force in the opposite direction of its motion. The delta t you use is for the particle to come back to its initial position (distance over velocity) and not the duration in which the particle experiences the net force by the container walls.

@vt.physics Жыл бұрын

You're right in saying that the time t should be the time in which the particle experiences the force. But in the derivation, we have made the assumption that the force exerted is an average force exerted on the particle between the two walls.

@ttbdah8583 3 жыл бұрын

That really helps. Thanks

@raka7743 2 жыл бұрын

woah that's fantastic. now i'll be able to remember it.

@muhammadahmad-yd3ht 2 жыл бұрын

outstanding explaination....

@harrambaloch8682 Жыл бұрын

It solves my big problem thank you so much stay blessed and keep it up 😘

@Anas-ll1yc Ай бұрын

Thanks. Very nice explanation

@Sridevi-wt6fk 3 жыл бұрын

It's very helpful 😀

@vampire77 2 жыл бұрын

Nice explanation and simple too...

@muhammadshahidi2328 2 жыл бұрын

Thank you so much 💓

@ac-jk9mz 2 жыл бұрын

thank you for this video

@NoMatterWhat279 2 жыл бұрын

But how can time of impact equal total Distance 2x/speed as It is the time for which collision happened,so distance travelled is negligibly small during collision,why did you consider time of impact as the total time taken for The particle to come back again?

@adarbarandalgic2730 2 жыл бұрын

@hlapik1685 Жыл бұрын

Exactly

@jizzyjjarold150 Жыл бұрын

WAIT SO HOW THEN SHALL THIS DERIVATION WORK?!?! NOOOO I DONT GET IT!

@AnsonCheung1049 Жыл бұрын

It consider all the gas molecule,which the impact time for each of the gas molecule varies from 0 to 2x/u,2x/u is come from the fact that the molecule have just hit the wall and leave with a velocity-u,and it require 2x of displacement back to the wall

@KrishnFolk-pi9rv 7 ай бұрын

Perfect video for students thanx a lot teacher 🙏🙏💐💐💐

@Shasha42819 2 жыл бұрын

Thankyou so much 🤗

@jonahmedics3344 Жыл бұрын

Thank you very much am wordless it helps a lot thanks fr

@samitabaral4700 2 жыл бұрын

Thank you so much

@shivamkukreja1991 2 жыл бұрын

You got a new subscriber

@andrewlee8340 Жыл бұрын

thanks sm this helped a log

@adarbarandalgic2730 2 жыл бұрын

How can we substitute the value of the time between collisions as a contact time for the impulse equation?

@vt.physics 2 жыл бұрын

You're completely right in saying that the two values of time are seemingly different. But in this derivation, we are using the average force exerted by each particle, so we have to make the approximation that the two t's are the same. Thanks for pointing this out!

@teddy_sg Жыл бұрын

@@vt.physics this actually goes back to the assumption that the contact time is negligible. We are not looking at the contact time anyway. Since the equation for the average force only cares about the time interval between each collision. The only issue I have with the explanation is that the 1/3 and the r.m.s idea are tight together. They shall be explained together instead of separately

@Shrey_31 Ай бұрын

This helped..👍

@copiryte9535 Жыл бұрын

Can you go through the more complicated derivation where the time between collisions isn't used in the rate of change of momentum I can't find any videos on youtube explaining it.

@doiturself..g.o.a.t3508 5 ай бұрын

It's the only correlating way of momentum with force where force is the ratio of momentum to time

@Tabbyisfriendly Жыл бұрын

yo it was really a good explanation but can you explain the last rms part

@prasannak9320 Жыл бұрын

Thankyou ma'am

@EDUCATIONFORTODAY 2 жыл бұрын

Very nice

@egesacollins9510 2 жыл бұрын

Asante sana mwalimu

@Manojkumar-qc8wr 3 ай бұрын

Great

@justaracoonchillinginatoilet69 Жыл бұрын

why do ypu divide by 3 and not times by 3, since theres 3 dimensions and we only accoutn for 1? very confused about this point

@vt.physics Жыл бұрын

You can think of multiplying pressure by 3 as there are 3 sides contributing to the pressure. And I took the 3 to the right-hand side of the equation by dividing by 3 (but that's the same as multiplying by 1/3).

@Dark-tk9xu 2 жыл бұрын

Since when speed (which in this case is 'u') is a vector? Why do you have -mu? Is u speed or velocity?

@vt.physics 2 жыл бұрын

the negative sign tells us the direction of motion The equation can be derived more rigorously, but this vid is meant to simplify it for high school students

@phoebehasvoicebreaks9443 2 жыл бұрын

saved my fricken life

@wayoflife3928 2 жыл бұрын

I have a doubt In here do we assume that acceleration =0 Since you consider delta t=2x/u In the video 2:06 part

@vt.physics 2 жыл бұрын

The acceleration is 2u/t. Remember how acceleration is a vector, so it takes into account direction. If the forward velocity is u, then the backward velocity is -u. So the change in velocity is 2u.

@GOD-qk7xp 2 жыл бұрын

🔥👍

@mitra2028 2 жыл бұрын

how the XYZ part is written V?

@vt.physics 2 жыл бұрын

If I multiply together the dimensions xyz (or width x length x height) then I get Volume. Capital V is volume here.

@mitra2028 2 жыл бұрын

@@vt.physics Thanks❣️

@amirhamza1091 2 жыл бұрын

Why the time of impact is time taken to reach where it started

@vt.physics 2 жыл бұрын

time 't' here is the time it takes for it to change its momentum by that particular amount

@amirhamza1091 2 жыл бұрын

@@vt.physics thanks so much

@abigokul1958 2 жыл бұрын

Actually the force calculated here's for the wall exerted on the molecule. So that the time taken here is calculated as that way

@physicsloverjoinmychannel2937 3 жыл бұрын

from WHERE U GATE 1/3

@vt.physics 3 жыл бұрын

the one-third takes into account that there are 3 dimensions

@GL-Broz 3 жыл бұрын

In india this is 11th standard physics 😣

@shivamkukreja1991 2 жыл бұрын

Same in our country

@Unknown4U1 5 ай бұрын

Same in KZ

@Himadri.S.Debnath 2 ай бұрын

Studying this in class 11 in Bangladesh

@user-kr7lb8fq8l Ай бұрын

@@Himadri.S.Debnath Bro same!!!!!

@undead0564 Ай бұрын

Brother its same in UK

@insertyourfeelingshere8106 5 ай бұрын

Big brain time

@wuttinanthailand 3 ай бұрын

The only problem here is how do we know that divide by 3 is correct?

@maltzXD 2 жыл бұрын

Why can we use t in distance / time? The t in impusle is the contact time with the surface. The travel time t in other parts of the box has nothing to do with the contact time.

@vt.physics 2 жыл бұрын

Let's imagine the space between the walls is infinitesimal. And also, that is the distance between two points when momentum changes.

@jizzyjjarold150 Жыл бұрын

@@vt.physics OH I SEE. IGUESSD IT!

@xxxxxx-ef3lj 6 ай бұрын

@@vt.physics but what if (as is normally the case), the box is large?