Viscosity and Poiseuille flow | Fluids | Physics | Khan Academy

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  • Опубликовано: 28 авг 2024
  • David explains the concept of viscosity, viscous force, and Poiseuille's law.
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Комментарии • 70

  • @jaymayhoi
    @jaymayhoi 9 лет назад +63

    Attempting to learn fluid dynamics and this is awesome, thanks. Makes me ponder how far reaching studying medicine is

    • @user-kb7oe5wr7c
      @user-kb7oe5wr7c 8 лет назад +13

      In the exact same place right now, our textbooks are complete shit, but thanks to this I just started understanding it.

  • @ShadeOtree
    @ShadeOtree 7 лет назад +43

    الله يدخلك الجنه من أوسع ابوابها
    there are doctors gain more than 300 SR (nearly 80$ ) to teach us for an hour what you said in this video ! Thank you so much

  • @theDeathJoy
    @theDeathJoy 3 года назад +2

    This explanation saved me where teachers failed. They keep redirecting me to formulas that are of no use and refuse to give a greater in depth explaination... So sad that college tuition is being wasted like that.

  • @alialobaidy4610
    @alialobaidy4610 5 лет назад +4

    I will name my first born after you.
    Also, someone just prayed for you to go to paradise in Arabic. This video literally creates world peace!

  • @s5960
    @s5960 9 лет назад +10

    Brilliant, no idea why this video has so little views

  • @sushanchamrugurung229
    @sushanchamrugurung229 7 лет назад +19

    it's awesome ..... better than textbooks

    • @ruirodrigues3596
      @ruirodrigues3596 7 лет назад +1

      ofc its better than textbooks thats why teachers exits. Now the majority of uni teachers are people without the gift of education and with 3 phds so they tend to complicate even the most simple shit.

    • @kimanhoanthi117
      @kimanhoanthi117 4 года назад

      literally. i couldnt understand a thing from my textbook so I had to come here.

  • @mahimapasricha6388
    @mahimapasricha6388 5 лет назад +5

    I m in love with your teaching.. U taught so nicely thanks.
    ~a new fan and subscriber

  • @2175Wook
    @2175Wook 7 лет назад +6

    A Fluid Mechanics problem that I'm trying to work out. A viscometer of the Redwood type has an oil-containing cylinder 4.75cm in diam and an agate tube 0.17 cm in diameter and 1.2 cm long. The oil surface, when flow starts, is 9 cm above the outlet from the agate tube. To allow for the sudden contractions at entry to the tube, the effective length of the tube may be taken as the actual length plus the tube radius. Making allowance for the decreasing head of oil, the viscous resistance through the tube, and the KE (kinetic energy) of discharge, calculate using arithmetical integration, the time required for 50 cm3 of an oil of viscosity 0.5 poise and specific gravity 0.92 to flow through the viscometer. How do you find the time? From this question, I have tried to use quadratic equation to solve for v, but it is proving more difficult than I thought

  • @OiynsoftCorporation
    @OiynsoftCorporation 5 лет назад +7

    10:50 draws that smile 😂

  • @vAman00
    @vAman00 7 лет назад +5

    I love your way of teaching 😭😭😭😭😭💓

  • @heiheihei60
    @heiheihei60 6 лет назад +1

    The explanation is so clear, and interesting

  • @abdulmuizadegbindin3520
    @abdulmuizadegbindin3520 7 лет назад +4

    excellent video

  • @majdal-awar752
    @majdal-awar752 2 года назад +1

    Amazingly explained!

  • @anshulbirwal5788
    @anshulbirwal5788 5 лет назад +2

    It helped me a lot ✌

  • @yazandouleh9088
    @yazandouleh9088 9 месяцев назад

    Highly appreciated, thank you so much

  • @yuta2349
    @yuta2349 4 года назад +1

    This was really helpful. Well explained :)

  • @bohdansenchyshyn9598
    @bohdansenchyshyn9598 5 лет назад +1

    Nice. Excellent!!!

  • @user-le2wu4yl7w
    @user-le2wu4yl7w 4 года назад

    Very good example and explanation for understanding. Thank you

  • @abhinavpa7688
    @abhinavpa7688 5 лет назад +1

    Very helpful thanks😍

  • @deviprasadpandey8518
    @deviprasadpandey8518 2 года назад

    Thanku so much sir you and your way of teaching is just amazing

  • @skilifavas4016
    @skilifavas4016 5 лет назад

    Someone give this guy Money

  • @debangana9964
    @debangana9964 7 лет назад +36

    This guy, whoever he is, is great 😂😂😂

  • @twominuteanaesthesia
    @twominuteanaesthesia 3 месяца назад

    Good stuff

  • @taylorneill2687
    @taylorneill2687 6 лет назад

    Amazing video, best Ive found thanks

  • @paoisaacleo882
    @paoisaacleo882 9 месяцев назад

    Thankyou

  • @salmagamal5676
    @salmagamal5676 5 лет назад

    LIFE SAVER
    as always

  • @antalenej3885
    @antalenej3885 2 года назад

    Thank you for this amazing video helped me a lot ❤

  • @zamramumthaz1428
    @zamramumthaz1428 6 лет назад

    Incomparable explanations awsome.....

  • @ashu.tosh_kumar11
    @ashu.tosh_kumar11 4 года назад +1

    Please can you write back me or give me ling of this question 👉on the view of viscosity and type of flow explane flood

  • @dhruvparmar4061
    @dhruvparmar4061 3 года назад

    How we can consider fluid that is in contact with pipe is stationary?

  • @dontarobta4439
    @dontarobta4439 6 лет назад +1

    Whats the formula for viscosity in a newtonian fluid?? How do we "ignore" the "v" thats already present in the formula???

    • @saramohamed.8403
      @saramohamed.8403 3 года назад

      Try watching "why is ketchup so hard to pour" by TED ... it is kinda helpful with this speed matter

  • @faizagha2362
    @faizagha2362 6 лет назад +1

    Wouldn't the viscous force be equal to the force applied because Newton said opposite and equal reaction to an action?
    Please can someone explain me that why can't we just say that the viscous force is equal to the force applied to the lid.

    • @faizagha2362
      @faizagha2362 6 лет назад +1

      And please if I have left some basics don't mock me just answer me

    • @Drew88317
      @Drew88317 6 лет назад

      Equal and opposite reactions wouldn't resign every action to inaction, that is to say things can still move and not be stopped by the so called opposite force. Assuming the edges of the box were frictionless you could determine to a decent degree the viscosity by applying an increasing force to the plank and seeing at what point it began to move. If we do in fact know the coefficient of friction between the edges and the plank then we can estimate the viscosity by looking at the rate of deceleration when the box is full and when it is empty. The opposite force in this case is that the water pushes back, but more of the water will be pushed forward in the plank's direction.
      TLDR: We know the forces aren't equal because the plank is moving. The breaking point between where it begins to move and is stationary would be an equal force to the viscosity.

  • @ushasri2462
    @ushasri2462 6 лет назад

    why did u consider velocity as speed in unit? Only that portion is not understood..same thing done in the book.

  • @RhodesW
    @RhodesW 6 лет назад +20

    If you play it on 2x speed the mannerisms of speech sound like Rick from Rick and Morty

  • @xxxx-xs5vr
    @xxxx-xs5vr 7 лет назад

    you are amazing thank u so much

  • @leeeeni
    @leeeeni 3 года назад

    Is the first flow called Couette-flow?

  • @BobProductions
    @BobProductions 3 года назад

    Why is P not cP??? When it’s 1/10th of Pa*s ???????

  • @tecnicaltecnical4356
    @tecnicaltecnical4356 8 месяцев назад

    There isnt in your videos translated in turkish can you add?

  • @Kencan254
    @Kencan254 6 лет назад

    In MCAT, is the Poiseuille formula provided?

  • @sophmiester
    @sophmiester 7 лет назад

    thats a dope box brah

  • @niko-ni6ps
    @niko-ni6ps 4 года назад +3

    Keep scrolling guys, I just randomly watched this at 3 a.m

  •  5 лет назад

    perfect.

  • @MikeSmith-ej4zv
    @MikeSmith-ej4zv 7 лет назад +2

    How would n not depend on velocity when n=f*d/A*v?

    • @davidkippy101
      @davidkippy101 7 лет назад

      Mike Smith Because F is also in the equation, and when v changes, so does the force, which compensates for the change in velocity.

    • @nicholasturo-shields6477
      @nicholasturo-shields6477 6 лет назад

      The viscosity is generally a material property, depending on the temperature and other relevant state factors. Whether you pull fast or slowly does not change this material property. (This is only true for Newtonian fluids. Non-newtonian fluids act differently and are really cool. I suggest you look up videos on them)

    • @saramohamed.8403
      @saramohamed.8403 3 года назад

      Try watching "why is ketchup so hard to pour" by TED it explained this speed thing

  • @tecnicaltecnical4356
    @tecnicaltecnical4356 8 месяцев назад

    Can you add subtitle in turkish.because I wanna improve my English

  • @leeeeni
    @leeeeni 3 года назад

    Poise is not longer allowed as unit for viscosity.

  • @abhinav3478
    @abhinav3478 6 лет назад

    Is unit of coefficient of viscocity is
    Kg/ms ?
    F = n A v/d
    n = Fd/Av
    = kg m s^-2 * m / m^2 * m s^-1
    = kg m^-1 s^-1

    • @nicholasturo-shields6477
      @nicholasturo-shields6477 6 лет назад

      This is also an acceptable unit for viscosity coefficient, yes (see en.wikipedia.org/wiki/Viscosity). -Engineering student at Purdue

  • @sahubabu5267
    @sahubabu5267 2 года назад

    Soothing accent

  • @aryazephyrnavin761
    @aryazephyrnavin761 3 года назад

    check out this empty box! now check out this lid I can put on empty box!

  • @bytheway1031
    @bytheway1031 2 года назад

    🎂Jean Poiseuille 04-22-2022

  • @thomasweyermann5848
    @thomasweyermann5848 4 года назад

    3:14 what I know you’re all here for

    • @fernandb.6162
      @fernandb.6162 3 года назад +1

      Thanks man.
      "What is a viscous fluid ?"
      It's *T H I C C K*

  • @sisyphus645
    @sisyphus645 3 года назад

    Wait...You're not Sal (but just as cool)

  • @saraemad7238
    @saraemad7238 2 года назад

    Plz add Arabic language in subtitles 🙏🗣️