Buoyant force example problems | Fluids | Physics | Khan Academy

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  • Опубліковано 3 гру 2024

КОМЕНТАРІ • 102

  • @syedrizvi2687
    @syedrizvi2687 3 роки тому +10

    I love your small interesting digressions when you teach! Your power in explaining concepts is phenomenal :D May God bless you in your mission of free World Class Education to all!

  • @bwibwi5
    @bwibwi5 10 років тому +64

    "It could have been shaped like a horse."

  • @achintyasingh2025
    @achintyasingh2025 Рік тому +1

    Your explaining language is so easy to gauge the concept. That anyone can get it’s complicated language to a simple one. Thanku so much

  • @anashassan4861
    @anashassan4861 3 роки тому +2

    13 years later and he's still a legend just wow.

  • @najjmx2422
    @najjmx2422 5 років тому +2

    i like how u casually start your videos like a casual convo

  • @asherzephyr
    @asherzephyr 15 років тому +1

    No, he got it right. Vs/Vb is telling you what percentage of the object is submerged while Ps/Pb is telling you the specific gravity. If you switched it, the whole proportion would be messed up and basically it would be saying the volume submerged is greater than the block itself. Then the object wouldn't be floating....

  • @Aishaelhouderi
    @Aishaelhouderi 12 років тому +7

    you are a legend, your videos always make me change the way i think about these problems. Could you please make videos about hydrostatics.I am really struggling with them. thanks again

  • @asherzephyr
    @asherzephyr 15 років тому +12

    Yes, the fraction submerged is equal to its specific gravity.

  • @i03i
    @i03i 4 роки тому +3

    thank you, now I understand buoyant force for my quarter exam

  • @omoolorunful
    @omoolorunful 13 років тому +4

    OMG thank you so much. I've been struggling with my tutorial question for ages, Now I get it!

  • @Noor-wc1ji
    @Noor-wc1ji 5 років тому +14

    i looked at his calculator and immediatly knew it is 2008

  • @elistidham8494
    @elistidham8494 3 роки тому

    best youtube ever hands down

  • @mariofrendoz7488
    @mariofrendoz7488 11 років тому +1

    Thanks Sal. This Video helped me a lot.

  • @RedVenomProductions
    @RedVenomProductions 7 років тому +2

    what i find very puzzling and confusing is in the buoyant force equation you have to put volume of water displaced ,but if the volume is the same for two objects and one of them has less mass and there both denser than water how would the bouyant force be the same for both if they have different densities. Please respond thankyou

  • @volintine
    @volintine 16 років тому +1

    thnx sal

  • @bilhassan4604
    @bilhassan4604 8 років тому

    This help me to finally understand this topic and question!!!!!!

  • @trentf8607
    @trentf8607 3 роки тому +2

    So this only works for blocks and horses. Good to know!

  • @johnmandrake8829
    @johnmandrake8829 7 років тому +1

    I appreciate you so much..honestly

  • @promiseoke6309
    @promiseoke6309 3 роки тому +1

    Thank you so much for this ...it is really helpful 😍

  • @BaRa6992
    @BaRa6992 13 років тому +1

    Khan ..! God bless u

  • @rockinrec22
    @rockinrec22 11 років тому +18

    great video im in 8th grade and I feel like the current curriculum is for 2nd graders so I started doing this in my spare time.

    • @pxatm
      @pxatm 11 років тому +2

      Hey Gavin can we forward this to like, teaching circles?

  • @Billabong024
    @Billabong024 13 років тому

    excellent example

  • @KaterMUC
    @KaterMUC 5 років тому +2

    How do you get from cubic meter to square feet? Missing a Dimension here?

  • @sergiomuniz350
    @sergiomuniz350 6 років тому

    Fluids made easy. Great stuff.

  • @jasondominicpereira1545
    @jasondominicpereira1545 3 роки тому +1

    Percentage of the Volume of that substance submerged would be specific gravity of that substance multiplied by 100

  • @shirasvlogs
    @shirasvlogs 7 років тому +1

    super eth nangalk prayojanam ullathan thanku

    • @lightningmcdweeb
      @lightningmcdweeb 6 років тому +1

      da malayalathil paranjal evanmarkonum manasalavathilya

    • @harikumart.t1907
      @harikumart.t1907 4 роки тому +2

      Malayalis here malayalis there malayalis everywhere pwoli

  • @Ryan-vw8gn
    @Ryan-vw8gn 10 років тому

    The net force downwards is 2N, but he's working out the volume of water displaced, so you use the buoyant force of 8N.

  • @siasorat
    @siasorat 13 років тому +2

    one person failed in life lol who the eff dislikes this video it made so much sense hope i could ace my final now lol

  • @saada8837
    @saada8837 8 років тому +2

    In the last video he said that Fnet = Pwater . gravity . d3 (volume) so why is he not using the net force of 2N and is instead using 8N force upwards?
    Also if the force down is 10N and force up is 8N then should this block just sink? what is the counteracting to prevent his block from sinking?

    • @jhonellemoore6684
      @jhonellemoore6684 6 років тому

      The block is sinking, that's why the net force is not equal to the weight of the object

  • @marcellohro
    @marcellohro 16 років тому

    the second example was beautiful!

    • @JoseShajiOfficial
      @JoseShajiOfficial 3 роки тому

      you thought the second example was beautiful 12 years ago

    • @marcellohro
      @marcellohro 3 роки тому

      @@JoseShajiOfficial Interesting... When I was watching this I was in high school. I concluded a graduation and master at mechanical engineering. Turns out I started not enjoying engineering and changed career.
      I think I changed my mind, the example is ok at best.

  • @anilceafp311
    @anilceafp311 8 років тому

    Very good!!

  • @chinoisbase
    @chinoisbase 10 років тому +29

    my textbook didn't express that important detail about Archimedes principle, but still ask a question directly from it. I hate my book

  • @calvinhobbesliker2
    @calvinhobbesliker2 15 років тому

    Does this mean that the fraction of the floating object submerges is equal to its specific gravity?

  • @Userwastaken
    @Userwastaken 13 років тому +5

    I wonder what the person was thinking when they clicked the thumbs down button...?
    I'm only in 8th grade, but my physics teacher wants me to take 4 pages worth of notes on this fluid series. Haha, it's a bit difficult to understand using only letters.

  • @UT.Rapstar
    @UT.Rapstar 8 місяців тому

    I love this place

  • @MrDod9
    @MrDod9 10 років тому

    Interesting video...

  • @treeislife93
    @treeislife93 6 років тому

    Sir I have some few question about density and buoyancy force
    No. 1 =Is hot water more dense or cold? i think cold is more dense.
    No. 2 = if cold water more dense what it mean is it more buoyancy?i think cold water more buoyancy.
    No.3 =if cold water more dense so does it help for swimming easily? i think cold water help swimming.
    No.4 =is water more dense mean more buoyancy easy to float or less dense mean less buoyancy difficult to float?

  • @FrinZHoN
    @FrinZHoN 12 років тому +1

    i wonder if its correct or not but the whole object is displaced therefore i would use the 10N.. ^^

  • @christophernasser9441
    @christophernasser9441 6 років тому

    good math!

  • @slmUSA
    @slmUSA 14 років тому

    Thank you!

  • @prithviraj7322
    @prithviraj7322 10 років тому +4

    in previous video you said that the net force equals the weight displaced...here the net force is 2N so shouldnt it be equal to the weight of liquid displaced?

    • @_DigitalRemake
      @_DigitalRemake 7 років тому

      prithvi raj buoyancy force is 8N

    • @jhonellemoore6684
      @jhonellemoore6684 6 років тому

      The buoyant force is only equal to the weight displaced when it floats, this is a sinking object, so the upthrust equals loss in weight

  • @Hellsslave666
    @Hellsslave666 14 років тому

    @spikeyredcactus
    devide both sides by VB and by PW and flipped sides.
    I tryed to write all stepps down, but it's really hard with a keybord xD

  • @johnsantos975
    @johnsantos975 3 роки тому

    I need to go back to school to keep up

  • @도목이
    @도목이 Рік тому

    와.정.말.재.밌.다

  • @aquienpuedaimportar3028
    @aquienpuedaimportar3028 6 років тому

    Why do we use g for the force acting on the bottom of the object? If the force acting on the bottom acts upwards and gravity acts downwards, why is g included?

  • @SAURABHKUMAR-dz5dt
    @SAURABHKUMAR-dz5dt 4 роки тому +1

    What do you know sir??

  • @repathon
    @repathon 15 років тому

    damn
    i wish i could use these videos on the ap test

  • @mbusomabuza7273
    @mbusomabuza7273 9 років тому

    do i have to memorize the densities

    • @agent475816
      @agent475816 9 років тому

      +mbuso mabuza No, they are usually given on the test. You probably have to know the density of water is equal to 1000 kg/m3

  • @Citicoper
    @Citicoper 6 років тому

    why it turns 240p

  • @redgrim7708
    @redgrim7708 3 роки тому

    how can you convert cubic feet to square feet?

  • @ccsargent
    @ccsargent 3 роки тому

    First problem error: he kept mixing sq in with in^3.

  • @ashokdas5645
    @ashokdas5645 7 років тому

    Nice

  • @angrypepecancer5205
    @angrypepecancer5205 7 років тому +1

    its really confusing when you convert it to ft^2
    and 1 cubic meter = 10.7639 square feet
    where did that 27 came from. Can someone explain.

    • @embeetwelve
      @embeetwelve 7 років тому

      He was doing very rough calculating just so you have an Idea of the size of the cube. There are roughly 3 feet in a meter, so there are 3^3 feet in a cubic meter which equals 27 cubic feet. He also misspoke.

    • @carlanw
      @carlanw 7 років тому

      The actual math is 0.0083 m^3 = 50.0395 inches^3. He miss notated it as ^2 squared but he is close for approximating. I hope that helps someone.

  • @joseguilfu4739
    @joseguilfu4739 6 років тому

    Why did you divide 1000 times 9.8? I thought you had to multiply it

  • @catindoyleonardorivera9627
    @catindoyleonardorivera9627 5 років тому +1

    w

  • @sodr2
    @sodr2 15 років тому

    couldve been SHAPED like a horse....i dont think a horse has a specific density

  • @bewaver
    @bewaver 5 років тому

    9.8 m per second squared is not gravity but acceleration...

    • @fyuira9585
      @fyuira9585 5 років тому +1

      nah not acceleration but acceleration due to gravity. And when he says gravity that what he means mate. hahah

  • @thenathan829
    @thenathan829 11 років тому

    i just love you so much

  • @nolsmtm
    @nolsmtm 14 років тому

    dont you mean cubed feet? (not square feet)

    • @zhto514
      @zhto514 5 років тому

      Are you still alive ?

  • @minetech4898
    @minetech4898 4 роки тому +6

    When being forced to watch this for school, I wish UA-cam had a 3x speed feature.

  • @joebender3662
    @joebender3662 7 років тому +1

    34 square inches I think not

    • @carlanw
      @carlanw 7 років тому

      50.0395 cubic inches but he was approximating from using the rough 27 cubic feet per cubic meter.

  • @dakshkholia8564
    @dakshkholia8564 2 роки тому

    a

  • @superduckduck
    @superduckduck 8 років тому

    when did the writing become so fuzzy

    • @925LY
      @925LY 7 років тому

      this video was made in 2008

  • @spacekatana8539
    @spacekatana8539 3 роки тому

    larry

  • @Premkumar-hj2dr
    @Premkumar-hj2dr 6 років тому

    🙂👍🏻

  • @dst7ssa
    @dst7ssa 15 років тому

    It could be a Horse ? hahaha good one

  • @rexgregorlaylo7724
    @rexgregorlaylo7724 9 років тому +4

    him: weight of water ... i dont know... 10N
    me: dafuq stating naive but giving its value anyway!

    • @vincenttran8415
      @vincenttran8415 6 років тому

      You know he's just coming up with some random number to use as an example.

  • @kacavvh
    @kacavvh 6 років тому +2

    read me bedtime stories plz

  • @Roadside33
    @Roadside33 4 місяці тому

    Import turtle