Surface Tension and Adhesion | Fluids | Physics | Khan Academy

David explains the concepts of surface tension, cohesion, and adhesion.
Watch the next lesson: www.khanacadem...
Missed the previous lesson? www.khanacadem...
Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.
About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to Khan Academy’s Physics channel: / channel
Subscribe to Khan Academy: www.youtube.co...

[@isabelaocampo5636]

" and your gonna be like oh thats so cool and youre gonna touch it, youre not supposed to touch it " looooolll i LOOOOVE IT

[@ally-xw2hj]

3:24 lol

[@bishakhashahrin3247]

best line of the video!

[@mustafaali3333-q1m]

That what she said

[@FunTime-zi1hi]

And then you break the surface tension and the water starts dripping this dude is so amazing oml

[@bookkkworm]

that's so cool and fun

[@ally-xw2hj]

" it is not floating, it is sitting on top of it " It helped for my science project! Thank you so much!

[@ShivaPrasad-hm5lk]

What was the project

[@tttrendsYT]

This helped me understand surface tension so much more! It really helped my science fair project!

[@bbthebot227]

same lol

[@shaunakn5881]

The thing that khan academy has helped us in studies and will do in the coming years is just, awesome! Khan academy rocks boy!

[@Gaku-tw3bd]

Most of the teachers used to make complications in this topic but you made it clear

[@angiem7030]

I was trying to understand surface tension and this video really helped me a lot! Thank you!

[@checkm8852]

Omfg!!!!!!! Finally a video that I can understand about surface tension. Thankyou!

[@n1tr1x8]

u r a true teacher sir...khan academy an teach anything

[@gathonimwangi6758]

SO COOL!!!! WHO KNEW I COULD FINALLY CRACK HOW SURFACE TENSION WORKS?! YOU ARE DEFINITELY MY HERO FOR TODAY :)

[@cuong8071]

You're really good at explaining. I had to learn this lesson at 3 4 times at home because my teacher make it even more complicated. But thanks to you, i understood the lesson. Thank you so much😍

[@akshattripathi5756]

the best thing is that they are giving free and quality education and not for any exams but for knowledge.

[@apurbabauri3878]

Thank you sir.....For explaining it very well.....I wish I could hit the like button thousand times....(Y)

[@chitranshbindal1874]

you should hit the like button 2 times😂🤣

[@chitranshbindal1874]

don't take it seriously the video was good

[@ShivaPrasad-hm5lk]

It might result in not liking for the 1000th time

[@winterblake3321]

@@ShivaPrasad-hm5lk odd numbers will result in liking. 1 time = like 2 times = not like. since 1000 isnt an odd number, it in fact will result in not likiing

[@jeteloriaga]

this is the video where i got the answer to my question why the name is surface tension! thanks so much, i couldn't understand this concept from the book i was reading nor from the other videos i watched before this!

[@Mohitkumar-mv8mj]

Well explained , thank you so much , it really helped a lot

[@nellyhoffman6194]

Im studying this for my LUNGS physiology khan academy is great

[@alheeley]

A few misconceptions there Vicki, surfactant isn't a chemical its the name given to a family of chemicals like detergents that lower surface tension, a surfactant cannot cause surface tension in the lungs or anywhere else, it reduces it. The lungs expand due to the action of the diaphragm muscles causing partial vacuum to expand and squeezing to contract, which sucks air in and out. This has nothing to do with surface tension in the lungs.

[@jellewolters6450]

Yes it does. Surfactant is an important aspect of the lungs, keeping the alveoli open. It decreases surface tension and thereby increases compliance of the lung, as well as making sure the lung does not collapse on expiration. Dipalmitoylphosphatidylcholine is an important surfactant in the lungs, made by type 2 epithelial cells. See Guyton, Medical physiology chapter 39 on pulmonary ventilation.

[@yaleiqiu7687]

best explanation I ever find!

[@vedantsingh8582]

You helped me in my exam. Thank you so much sir

[@guruofeverything6379]

Finally, somebody who explains it properly !!!!

[@hongkijeremy5236]

3:24 that line or explanation is so like Alexander Lightwood towards almost everyone... Except Magnus.. Lol, anyway, back to my general chemistry exam. 😵😵😵

[@kgkmurthy1961]

very very nice analysis and backed by day to day examples...good

[@Photosynesthesia]

very accessible to people like me with minimal knowledge of this stuff, great explanation - thanks!

[@science-y9209]

thanks a lot . I can't tell you how thankful I'm for such a, such a nice explanation

[@corrupted9588]

i have been enlightened

[@dishayanmandal]

This is really impressive Thank you so much Sir

[@ArielStar]

This was amazingly and simply explained!!

[@08athakwaninandish16]

आपका विवरण सुनके द्रव का पृष्ठ तनाव अच्छे से समझ गया। Dude your explicit explanation cleared all the doubts. ⭐

[@chimerenwoji4458]

You really helped a lot. Thank you so much

[@sophiechuen5707]

U explain it so well, thank you!

[@ffveteran2309]

You really made it easy and time saving

[@omengdadong7703]

What principle in physics behind the surface tension?

[@vedbhobe9420]

too good to clear the concepts, khan academy is the best

[@bizarrelance3698]

These videos are life savers.

[@cikif]

Is there a relation between the polarity of a liquid and its surface tension?

[@apurvnikum3866]

short and sweet explanation.

[@aaranyachaturvedi6225]

Probably the best vdo on this topic

[@olajumokealbert6578]

Thanks

[@danraul9759]

Man you made this so easy to understand...

[@harshvardhanmankotia6492]

Will salt composition in the water affect the surface tension.

[@thenujansandramohan8930]

HarshVardhan Mankotia yeah it will reduce surface tension

[@danielb.6184]

Very nice explanation, thank you very much!

[@user-hv6ef9ie1g]

Nice explanation!

[@abhishekashegoes5957]

Thank you sir...Thank you so much!!

[@logicalphallusry]

So glad I watched this before I got in a bizarre gambling situation in Egypt years ago.

[@mananwashere]

huh ?

[@medoviski3754]

huh?x2

[@saltypakoda5333]

Yo mr joster

[@rafudiasona]

We will never escape jojo's reference

[@bipasharouth4585]

Thanks sir

[@mayurakshisingh5922]

sir if an object is floating ....then what does it mean ....like whether it would be moving on the surface of water or just stay stationary at that place if, the density of the obj. is smaller than the density of water.............

[@maryamtanveer307]

Thanks for making the khan academy best channels for everyone love u i user to watch your videos your way of explaining also gives the very right concept and no doubts are left behind

[@Vigi]

Great! Easy to grasp!

[@FAnizah_edits29]

what if you put something with a really high density, higher then the water?? Will it sink or float because of adhesion.

[@princessesshusha8837]

Thnak you 🌸

[@makoxd1178]

is thank you not thnak :v

[@caj5140]

DONT ASSUME THE GENDER OF THE WATER MOLECULES!!!!! 1:30

[@slykhajiit2]

hahahah

[@tenzingobom4748]

so u just came here for that ? dummass

[@imenehk2221]

AHAHAHAHHAHHAHAHHAHAHHAHAHAHHAHAHAHHAHHAHAHHAHAHAHAHHAHAHHAHAHAHAHAHAH

[@tenzingobom4748]

He was right .. u can mention water as a guy as water r calm and always dilute other substances

[@swatikamat1281]

@@tenzingobom4748A joke, bro.

[@Honey_Bun_34]

THANKS A LOT HELPED ME A BUNCH

[@Harekrishnahariom7]

.....and i was struggling with this!!!

[@amileye6924]

I get it a lot better. Well explained .Thank you!

[@salasplayz2597]

Best video out there

[@nitink9879]

But for the liquid molecules on the surface, since there is no molecules above them, there will be a resultant force acting in the downward direction . This must help the needle penetrate the liquid. So why don't we consider this into account ? Why are we only considering the surface tension (which is due to forces on left and right side)

[@snakecodm7249]

NaHBro...the tension acts like a lair to keep the needle up. The net force downwards on the molecules just "tightens" the surface

[@Yankee4ever2]

what a lesson

[@shikhanshu]

What an awesome explanation!

[@Gaku-tw3bd]

Clearly explained well done sir.!!! Understood clearly 😀

[@biyahanashii7832]

thanks. our subject physics is making me confused since we don't have face to face classes

[@iYakuza11]

Well done, Sir. Amazing explanation 👏

[@King_4r7hur01]

So what’s holding up the needle is buoyant force or is that different from surface tension?

[@mtflieutenant7693]

Surface tension is basically one of the best chapters of Half Life 1

[@artefukurou851]

so surface tension occurs when the molecules that are in random motion bonds with each other that the ones above have to bond with each other cause there is a strong cohesive force between them. As the molecules on the surface bonds it forms a tension on the surface...so surface tension??

[@saysmil6k]

it makes sense now. thanks

[@yogeshkumarmatlapudi9603]

Excellent ly explained sir

[@lishanpereira343]

thx mate

[@peng8151]

great video and examples!

[@CEmpty2044]

I was hearing a music Video named "Surface Tension" then youtube recommends me this Oh god our Beloved KZbin.

[@alansamkutty6472]

Thank you sar your class was very very good👍👍👍

[@prabaljyotichoudhury8448]

Good and correct explanation 👍

[@j_ken3424]

GO AHEAD, MR JOESTAR

[@stray_demon]

Wtf how did u read my mind fkkkk lol

[@Shelf0808]

What does this have to do with jojo?

[@j_ken3424]

@@Shelf0808 yare yare, watch part 3 you moron

[@sheme110]

The angle at the meniscus for water is it zero or not?

[@elciobarrosmendoncafilho9353]

Is liquid adhesion the same of CAPILARITY?

[@muzamelpamir4336]

Very well explanation

[@anushkarajora8084]

Loved it thanks sir

[@sherazkhan2802]

But what about the lateral and bottom molecules in a glass ... They also experience as unblanced force so why not the water squeeze in the container ...Why doesn't it bocome a big drop in the glass?

[@sughraagha5551]

Because of adhesive force of water with container, the water can't turn into spherical shape.

[@ksakhilesh123]

Awesome explanation bro

[@0ello0]

Thank you sooooo soooo much

[@ramolamim2851]

interesting, thanks a lot for that, any video about contact angle ???

[@makoxd1178]

Here is the Link of the Video about contact angle kzbin.info/www/bejne/jWSqo4aDjseeeKc

[@stebobibo]

Why would the water seep into your tent from touching the inside of your tent? Never really explained that, just said "cause surface tension".

[@prabhatkiranchaulagain1095]

Good explanation. Love it Samikshaa Aryal !!!!!!!

[@prabhatkiranchaulagain1095]

*You Samikshaa Aryal

[@moa9644]

Thanks a lot ❤️️

[@anandsharma9509]

very nice video!!!!

[@goodToBeConfidential]

what is capillary inversion??

[@memo6032]

Can't thank u enough ❤❤

[@Hello-qy8vk]

thanks

[@akashsingh-xe3bq]

Really cool

[@mahimapasricha6388]

Great!

[@FluidMatters]

A steel needle floats because of the combined effects of surface tension and hydrostatic pressure on the wetted portion of the needle. Not surface tension alone. An over simplification of the physics.

[@owenjardaneh9113]

i have a question, and excuse my ignorance, anyone can chime in. is there a way to make water remain in tension or increase the cohesion so that water can contain itself? its a bizarre question and making it happen would probably break a lot of rules about physics and chemistry.

[@ambarishphysics]

CHECK OUT MY ORIGINAL SOLUTION TO A TRICKY SURFACE TENSION CHALLENGE HERE: kzbin.info/www/bejne/bnirpauFmbqejqc

[@neat_copper9613]

*Music plays* Liquid Lover. Froze this water. Into stone. In many tones. Fear uncovered. Melts this Molten. Ray of gold. Let it roll. I feel us sinking. Looooooowwwwww. Like surface tension in you. Woooaaaaahhhh. Feels much better down be. Looooooowwwwww. Like surface tension in you. Woooaaaaahhhh. Feels much better here you know. *music plays* Like surface tension. *Music plays* Here we go! Surface tension by Teminite and Prosgnar

[@AnonymousAlien2099]

Mind blowing

[@akhmadjonovakromjon3669]

The best!

[@dwdekort]

This explanation does not make sense. The needle keeps floating because, when the needle would sink from the surface into bulk of the liquid, there is an energy penalty associated with breaking the water bonds and forming a larger metal-water interface instead. The molecules at the surface do not attract one another more strongly than in the bulk of the fluid! Further to this, the molecules within the fluids do not have a fixed position at all but exhibit “random walks” - self diffusion. For water at 298K the self diffusion coefficient is about 2E-9 m^2/s

[@arshkashyap4434]

Nice

[@denizcetin675]

If surface tension keeps water molecules on the surface closer together locally, why don't they come down from a local density difference?

[@lordvenkatswara8727]

Ossum explanation

[@cybercop3108]

Lord Venkatswara ossum?

[@moism]

amazing

[@shahin2324]

Well explained!!!