Archimedes principle and buoyant force | Fluids | Physics | Khan Academy

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  • เผยแพร่เมื่อ 7 พ.ย. 2024

ความคิดเห็น • 119

  • @arnoldchristian9501
    @arnoldchristian9501 7 ปีที่แล้ว +124

    Bro how do you know every single thing in the world? lmao

  • @joeymama648
    @joeymama648 11 ปีที่แล้ว +11

    his voice is SOOOOO relaxing

  • @artakisthebest
    @artakisthebest 12 ปีที่แล้ว +25

    hehe, I actually only made it halfway through his trigonometry playlist the day before my trig exam havving never looked at my other teachers notes, and got 84 percent in my trig exam! And that was a college level test :D

  • @kanaeroseweld2237
    @kanaeroseweld2237 ปีที่แล้ว +1

    Thanks bro. I have been trying to undertsand this principle for hours. You saved me days of trying to think. Thanks

  • @dst7ssa
    @dst7ssa 15 ปีที่แล้ว +4

    Funny I have a fluids exam tomorrow and am gaining confidence as I watch your videos. I cant believe I didn't see this before my first exams. Now I feel like I understand enough to actually teach someone. Captain Sal explain things so simply like you do . thanks

    • @Smokie_bear9896
      @Smokie_bear9896 6 ปีที่แล้ว +1

      woah you’re from the past

    • @ottavari746
      @ottavari746 6 ปีที่แล้ว

      Smokie Bear lol

    • @Aalijah_Matyevna
      @Aalijah_Matyevna 2 ปีที่แล้ว +1

      Were you in college at that time?You have grown up so much now then.

    • @amirabbas0
      @amirabbas0 ปีที่แล้ว

      @@Smokie_bear9896 now you're from the past

    • @Smokie_bear9896
      @Smokie_bear9896 ปีที่แล้ว

      @@amirabbas0 now i'm from the present

  • @TACZero1
    @TACZero1 12 ปีที่แล้ว +2

    My teacher for some reason made us learn fluids by ourselves, which i think is the hardest thing we've done so far. so thank you for your videos because i have been so lost

  • @sehmio
    @sehmio 7 ปีที่แล้ว +13

    This was fantastic! Background in why its F=pvg!

  • @MellowCruisin
    @MellowCruisin 14 ปีที่แล้ว +1

    I have a question for you. If an object is at the very bottom of a jar of water with no room for water between the object and bottom of jar, how does the object still buoy up if there isn't water below it?

  • @ModernWoodShop
    @ModernWoodShop 6 ปีที่แล้ว +74

    "If you can't explain it simply, you don't understand it well enough." -Albert Einstein

    • @the_unconscious_mindthe_le3344
      @the_unconscious_mindthe_le3344 6 ปีที่แล้ว +2

      Maxwell Gunter 😂😂😂😆😃

    • @Ndfull
      @Ndfull 2 ปีที่แล้ว

      @@the_unconscious_mindthe_le3344 1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqquq

    • @Ndfull
      @Ndfull 2 ปีที่แล้ว

      @@the_unconscious_mindthe_le3344 0000000

  • @abdosamr4639
    @abdosamr4639 2 ปีที่แล้ว +1

    Pressure acts in perpendicular directions, not in all directions.

  • @megaelliott
    @megaelliott 15 ปีที่แล้ว +2

    Look up rho(greek alphabet) on google and you will see that the capital version looks slightly different. I advise that you use that as rho in your own work as it is less confusing

  • @sureshchandrapal2320
    @sureshchandrapal2320 3 ปีที่แล้ว +1

    Thank u so much....I was extremely confused in it but now it is crystal clear ....thank u million times
    Hare krishna

  • @nenoo1536
    @nenoo1536 2 ปีที่แล้ว +2

    this is actually really helpful!! bless you :)

  • @NilanjanaLodh
    @NilanjanaLodh 14 ปีที่แล้ว +1

    really wonderful!!no other video on the net is as good as urs!u jus rock

  • @niconikko
    @niconikko 13 ปีที่แล้ว +3

    Mr. Sal, you're not just a great teacher, but you're also a great magician. You helped us in showing the formula for buoyant force like magic. THANKS!!!

  • @SwayamKrishnaartsandcrafts
    @SwayamKrishnaartsandcrafts 11 หลายเดือนก่อน

    It has been 15 yrs but still this video helps

  • @htavli
    @htavli 2 ปีที่แล้ว +1

    This video was very helpful. Thank you!

  • @ArchmageMokokong
    @ArchmageMokokong 6 ปีที่แล้ว

    his voice is sooo relaxing and his video is so wonderful teacher to me.

  • @artakisthebest
    @artakisthebest 12 ปีที่แล้ว +7

    respect man, figuring things out for yourself will really make sure it sticks in your brain! I aspire to be an engineer, and I could never just 'trust' in all the formulas I use, Id like to prove them myself. I hope I can say the same when im in the last year of my degree where things are bound to be not as intuitive. At the moment im having trouble grapsing the concept of Enthalpy. Do you think you could explain enthalpy for me :P

    • @soumyashreebiswal14
      @soumyashreebiswal14 2 ปีที่แล้ว +1

      Absolutely agree with you, man! Same aim here, and I too always try to prove stuff myself. Not a bad habit to have, is it? (Jeez when you commented this, I was like 8 years old haha)

  • @nu.wa.n
    @nu.wa.n 8 ปีที่แล้ว +10

    the explanation that finally ties it all to weight is really really neat.

  • @MitchelChabu-yl2xp
    @MitchelChabu-yl2xp ปีที่แล้ว

    You make me want to say I love physics

  • @bubbybumble616
    @bubbybumble616 3 ปีที่แล้ว +1

    bro how does this video from 2008 perfectly explain one of the harder concepts for me to grasp. how did I not understand this before?

  • @josemolina5423
    @josemolina5423 7 ปีที่แล้ว +7

    Water molecule as a sphere?
    J. Dalton likes this

  • @firaolmulugeta9928
    @firaolmulugeta9928 3 ปีที่แล้ว +1

    wow very nice i uderstand every thing what he says

  • @Chelsea-gs7qj
    @Chelsea-gs7qj 7 ปีที่แล้ว +53

    I usually love these videos but I'm literally lost

    • @keamorshedsoccer1382
      @keamorshedsoccer1382 7 ปีที่แล้ว +3

      Chelsea Osuji Khan made this video wayyyyyy to mathematic🙏🏽😬

  • @psbbiaku640
    @psbbiaku640 7 ปีที่แล้ว +1

    hey sal I am ur no.1 fan

  • @slmUSA
    @slmUSA 14 ปีที่แล้ว +1

    Thank you!

  • @nolwazihlophe580
    @nolwazihlophe580 5 ปีที่แล้ว +1

    thank you

  • @stephenkong3155
    @stephenkong3155 7 ปีที่แล้ว +1

    May I ask why does the net force equals to the buoyant force? Like what's the reason they equal?

  • @vinayseth1114
    @vinayseth1114 8 ปีที่แล้ว +3

    But shouldn't the net force be 0, otherwise the cube would keep jutting upwards and then get pushed out of the water?

    • @amrshehab7019
      @amrshehab7019 6 ปีที่แล้ว +2

      It is another thing he is just calculating the net force due to the pressure difference which is called buyonce force but there is also another force which is the gravity so when we apply neowton’s second law on this body we will say that the net force = mg (gravity[downwards]) - B (buyonce force[upwards])
      And if they are equal it will be submerged in the fluid if the gravity is greater it will sink if buyonce force is greater it will float untill some of it get out of the fluid that the dicplaced fluid is less so the buyonce force is less to be in equilibrium with the force of gravity

  • @sergiomuniz350
    @sergiomuniz350 6 ปีที่แล้ว

    great video. in the book they have f= gamma times the volume in which you have d cubed times rho times gravity and rho times gravity makes gamma so that explains a lot.

  • @kanikachaudhary6089
    @kanikachaudhary6089 3 ปีที่แล้ว +1

    ONE QUESTION HOW PRESSURE ACTING IN ALL DIRECTION IT SHOULD ACT DOWNWARD ONLY HOW LEFT AND RIGHT

  • @BettyNalugo-et9sp
    @BettyNalugo-et9sp ปีที่แล้ว

    so wonderful 💖

  • @anber4129
    @anber4129 5 ปีที่แล้ว

    Beautifully done. Very easy to follow. Very flowing.

  • @MandaNovokmet
    @MandaNovokmet 7 ปีที่แล้ว +1

    This is a beautiful video!! Really made the concept clear, thank you! God bless

  • @willpaisley7828
    @willpaisley7828 7 ปีที่แล้ว +3

    Does this assume the mass of the cube is negligible

  • @rotflmaopmpqxyz
    @rotflmaopmpqxyz 14 ปีที่แล้ว +1

    So P stands for pressure, and p is also units for momentum AND density? these confuse me. Also Mass and meters confuse me too

  • @KavangWase
    @KavangWase 9 หลายเดือนก่อน

    I'm confuse. Fnet=(d•p•g)d^2 if you are going to expand that, why does both density (p) and gravitational acceleration (g) are not multipled by d^2 and only d is multipled by d^2 giving d^3?

  • @artakisthebest
    @artakisthebest 12 ปีที่แล้ว

    Wow that was a very intuitive example my friend! Did you read that somewhere or you thought of it, I think thats beautiful, really complements the mathematical proof of archimedes principle well.

  • @flimsyfox
    @flimsyfox 4 ปีที่แล้ว

    I just had a "mind-blown" moment.

  • @SAISRIKAR2002
    @SAISRIKAR2002 5 ปีที่แล้ว +3

    What happened to the wEight of the cube while calculating the net force?

    • @Jay-jk7jv
      @Jay-jk7jv 3 ปีที่แล้ว

      The net force calculated here is the force acting on the cube due to pressure. The weight of the cube is acting downwards while the net force due to pressure is acting upwards. That means the net force due to pressure will work against the weight of the cube. This is what makes the cube feel lighter when it’s in the liquid.
      I'm 2 years late, but I just learned this concept from this video and thought I should answer. You know, just to see if I can explain it:)

  • @SkyOnUrSide
    @SkyOnUrSide 2 ปีที่แล้ว +2

    ITS FREAKING 2022 it was 2008 dayum

  • @ParadiXe311
    @ParadiXe311 3 ปีที่แล้ว +2

    This video was so educational, I just jumped out of the bathtub, running down the street naked, yelling "Eureka!"

  • @specialparadise
    @specialparadise 7 ปีที่แล้ว +7

    Anyone else had a Eureka moment?

  • @CcanCcaglar
    @CcanCcaglar 14 ปีที่แล้ว +3

    omg khan when im rich im guna give you so much money

  • @ANUPAMAMATHEWPHD
    @ANUPAMAMATHEWPHD 6 ปีที่แล้ว

    Is the box in static equilibrium or is it moving up??

  • @hemantvaish5658
    @hemantvaish5658 7 ปีที่แล้ว

    good vidd
    sir plz aaap practically videos banayq karo
    jaise aaap specific gravity ki bnayai hh
    vry nyc vidd
    plzz

  • @himanshusharma9981
    @himanshusharma9981 6 ปีที่แล้ว

    nice derivation, but what if we take the example of a human being and try to derive Archimedes principle .how will u take out the volume of a human.

  • @maxtan4471
    @maxtan4471 3 ปีที่แล้ว

    Why the force act on the top and bottom of the cube are not the same, since it is in static form?

  • @mousaalsaeed9410
    @mousaalsaeed9410 7 ปีที่แล้ว +1

    what happened for weight of object ??

  • @reesejpuc
    @reesejpuc 14 ปีที่แล้ว +1

    sal, 100 years from now, you will have your own unit of measurement named after you. The sal or the kahn.

  • @amrshehab7019
    @amrshehab7019 6 ปีที่แล้ว

    But this prove is for regular body how could we apply archemedis principle for spheres and irregular bodies ?

  • @fablihakhan9265
    @fablihakhan9265 7 ปีที่แล้ว +2

    Why am i not taking the height from the very bottom of the cup to determine the pressure at the bottom of the cube?

    • @fablihakhan9265
      @fablihakhan9265 7 ปีที่แล้ว

      Since the water from below the cube is also exerting some pressure on the cube

    • @36sufchan
      @36sufchan 7 ปีที่แล้ว

      If you consider height from the bottom; then it would make pressure higher at more distant points from the Earth (slightly less acceleration due to gravity); but since it doesn't work for columns infinitely long, it is not acceptable.

  • @gretawilliams8799
    @gretawilliams8799 7 ปีที่แล้ว

    That's through physics perspective but...
    The answer of why upthrust is created, is purely philosophical...
    Does pure water produce upthrust?? I think, upthrust effect is due to the repulsion between same charged ions....
    How do you put it(philosophy) into science ...
    The tendency of any body to remain undisturbed or in their natural state, upthrust is due to them resisting disturbance,.
    That's basically all upward directed forces: Normal contact force, Upthrust, ....

  • @illiums410
    @illiums410 7 ปีที่แล้ว +6

    Hotel?

  • @adas2922
    @adas2922 11 ปีที่แล้ว

    thanks

  • @sheme110
    @sheme110 4 ปีที่แล้ว

    Isn't pB also acting downward not upward?

  • @fufuisgood
    @fufuisgood 6 ปีที่แล้ว

    I did not quite understand "volume of the water displaced" I'm from Denmark and your videos are very helpful, but there's one thing that I did not quite catch..

    • @Arafat-my6fe
      @Arafat-my6fe 4 ปีที่แล้ว +1

      when u stick an object into the water, and exactly where u stick it into the water, the water of that very place has to move out to make room for the object u r sticking or putting there. And the volume or amount of water was moved(displaced) is called the volume of the water displaced. Hope, that helps. 😀

    • @fufuisgood
      @fufuisgood 4 ปีที่แล้ว +1

      @@Arafat-my6fe thankyou!! I totally forgot about it since it was 2 years ago ahahah

  • @dravinashiyer936
    @dravinashiyer936 5 ปีที่แล้ว

    With the hydrostatic eqn derive bouyant force of submerged body.. Put answer of this question please

  • @LNasterio
    @LNasterio 12 ปีที่แล้ว

    Imagine a cup of water as a box of solid balls.
    when you sink into middle of that box of solid balls.
    the balls on top will apply a force acting you downwards right?
    and the balls at the bottom of you will apply a "reaction force" acting on you upwards, And this reaction force is equal to weight of the object within the water plus the "balls"
    on top
    hope it make sense?

  • @drdkvetbiotech
    @drdkvetbiotech 7 ปีที่แล้ว +4

    why didn't we multiply d^2 with g and rho?

    • @rjk368
      @rjk368 7 ปีที่แล้ว +3

      I believe it was (dpg)*d^2. However, (dpg) means (d*p*g), not (d+p+g). So, it is (d*p*g)*d^2. Now, multiplication is commutative (can be done in any order) and associative (grouping doesn't matter if all operations are multiplication). Since all of the operations are multiplication, it is: d* p * g * d^2 = d * d^2 * p * g = d^3 * p * g. The reason you don't distribute is because you only distribute the coefficient when the operation inside the parentheses is addition (for example, 2(4+6) = 2 * 4 + 2 * 6 = 8 + 12 = 20).

    • @91755103
      @91755103 7 ปีที่แล้ว

      It's just to show that the buoyant force is the product of the volume displaced by the submerged object, and the liquid's specific weight.

  • @arulselvan4067
    @arulselvan4067 5 ปีที่แล้ว

    Buoyant force is the same as upthrust right? Sorry my English isn't that good

  • @arfaouiarij8938
    @arfaouiarij8938 6 ปีที่แล้ว

    I'm confused why you never spoke about the force of gravity ?

  • @Ichneumonidae2
    @Ichneumonidae2 12 ปีที่แล้ว

    great video, thanks!

  • @usersersandrenfcgami
    @usersersandrenfcgami 4 ปีที่แล้ว

    why did he ignored the weight of the cube when calculating the net force ?

  • @DbzFighter02
    @DbzFighter02 12 ปีที่แล้ว +1

    2 years later, I'm in the exact same position. LOLLLL!

  • @Henryy97
    @Henryy97 9 ปีที่แล้ว +5

    i love you.

  • @taymrafid9139
    @taymrafid9139 3 ปีที่แล้ว +1

    My guy made the video before I was born lmao

  • @rachellepangilinan5201
    @rachellepangilinan5201 2 ปีที่แล้ว +1

    We have a kid typing

  • @erikm9768
    @erikm9768 8 ปีที่แล้ว +24

    Jesus what a mess. Also, i was hoping to understand how pressure actually affects archimedes

  • @anotherdoseyt
    @anotherdoseyt 7 ปีที่แล้ว

    So straight to a cup of water... no good morning 😂

  • @Makedonche
    @Makedonche 14 ปีที่แล้ว

    @reesejpuc I'd go for the sal.

  • @midnightsilverpuppy
    @midnightsilverpuppy 7 ปีที่แล้ว

    That's interesting

  • @spatel6230
    @spatel6230 3 ปีที่แล้ว +1

    when Sal cancelled out those two phg's, I may have been more aroused than I've ever been in my life

  • @23Foxford
    @23Foxford 10 ปีที่แล้ว +4

    Love his videos, but his idea of fun with friends can result in pretty awkward situation

    • @brightface5005
      @brightface5005 8 ปีที่แล้ว +2

      i wonder if you would reply to this

    • @yiumyoumsan6997
      @yiumyoumsan6997 4 ปีที่แล้ว

      @@brightface5005 I wonder if you would reply to this.

  • @eniamrahc73
    @eniamrahc73 6 ปีที่แล้ว

    I love you so much.

  • @yashilakra5474
    @yashilakra5474 7 ปีที่แล้ว

    The voice is very slow

  • @sheu_her
    @sheu_her 7 ปีที่แล้ว

    Thats is not a P, please

  • @yashilakra5474
    @yashilakra5474 7 ปีที่แล้ว

    The

  • @Somali_omega
    @Somali_omega 11 ปีที่แล้ว

    not what i was looking for mate. Salman can do better

  • @samiyahshua
    @samiyahshua 7 ปีที่แล้ว

    #flatearthproof

  • @samiyahshua
    @samiyahshua 7 ปีที่แล้ว

    #flatearhclues #flatearthproof

  • @jaggitsingh9892
    @jaggitsingh9892 3 ปีที่แล้ว

    i just dont understand....i am in 6th grade and my mother makes me learn these things....... lol

  • @kenneffy1
    @kenneffy1 14 ปีที่แล้ว

    woah. lol

  • @Perrihan
    @Perrihan 5 ปีที่แล้ว

    Thank you so much!

  • @eslamnoaman3802
    @eslamnoaman3802 5 ปีที่แล้ว +4

    why we don't say that pressure at the top is equal to (roh+g+h+p atm)?

    • @ahsansafeer5246
      @ahsansafeer5246 4 ปีที่แล้ว

      It's a vacuum I guess

    • @benricosimamora3429
      @benricosimamora3429 4 ปีที่แล้ว

      (in case someone is still confuse about this). the pressure that was mentioned must be gage pressure (not absolute pressure) which is relative to atmospheric pressure, so we dont need to add p atm.

    • @predatorgaming895
      @predatorgaming895 3 ปีที่แล้ว

      @@ahsansafeer5246 no gauge