Archimedes principle and buoyant force | Fluids | Physics | Khan Academy
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- čas přidán 18. 04. 2008
- Introduction to Archimedes' principle and buoyant force. Created by Sal Khan.
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Bro how do you know every single thing in the world? lmao
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
wow you just made so MUCH SENSE
you have a gift for teaching.
that never made sense to me before.
thank you so much
his voice is SOOOOO relaxing
"If you can't explain it simply, you don't understand it well enough." -Albert Einstein
Maxwell Gunter 😂😂😂😆😃
@@the_unconscious_mindthe_le3344 1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqquq
@@the_unconscious_mindthe_le3344 0000000
This was fantastic! Background in why its F=pvg!
I usually love these videos but I'm literally lost
Chelsea Osuji Khan made this video wayyyyyy to mathematic🙏🏽😬
This is a beautiful video!! Really made the concept clear, thank you! God bless
Thanks bro. I have been trying to undertsand this principle for hours. You saved me days of trying to think. Thanks
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.
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
really wonderful!!no other video on the net is as good as urs!u jus rock
Water molecule as a sphere?
J. Dalton likes this
Beautifully done. Very easy to follow. Very flowing.
This video was so educational, I just jumped out of the bathtub, running down the street naked, yelling "Eureka!"
😂
this is actually really helpful!! bless you :)
Pressure acts in perpendicular directions, not in all directions.
This video was very helpful. Thank you!
Does this assume the mass of the cube is negligible
his voice is sooo relaxing and his video is so wonderful teacher to me.
It has been 15 yrs but still this video helps
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
woah you’re from the past
Smokie Bear lol
Were you in college at that time?You have grown up so much now then.
@@Smokie_bear9896 now you're from the past
@@amirabbas0 now i'm from the present
Thank u so much....I was extremely confused in it but now it is crystal clear ....thank u million times
Hare krishna
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!!!
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
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)
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?
Same😭
May I ask why does the net force equals to the buoyant force? Like what's the reason they equal?
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?
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.
Is the box in static equilibrium or is it moving up??
Thank you!
ONE QUESTION HOW PRESSURE ACTING IN ALL DIRECTION IT SHOULD ACT DOWNWARD ONLY HOW LEFT AND RIGHT
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
I just had a "mind-blown" moment.
Anyone else had a Eureka moment?
What happened to the wEight of the cube while calculating the net force?
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:)
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?
the explanation that finally ties it all to weight is really really neat.
But shouldn't the net force be 0, otherwise the cube would keep jutting upwards and then get pushed out of the water?
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
good vidd
sir plz aaap practically videos banayq karo
jaise aaap specific gravity ki bnayai hh
vry nyc vidd
plzz
what happened for weight of object ??
You make me want to say I love physics
hey sal I am ur no.1 fan
Thank you so much!
so wonderful 💖
wow very nice i uderstand every thing what he says
With the hydrostatic eqn derive bouyant force of submerged body.. Put answer of this question please
omg khan when im rich im guna give you so much money
Why the force act on the top and bottom of the cube are not the same, since it is in static form?
sal, 100 years from now, you will have your own unit of measurement named after you. The sal or the kahn.
thank you
why we don't say that pressure at the top is equal to (roh+g+h+p atm)?
It's a vacuum I guess
(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.
@@ahsansafeer5246 no gauge
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.
So P stands for pressure, and p is also units for momentum AND density? these confuse me. Also Mass and meters confuse me too
Why am i not taking the height from the very bottom of the cup to determine the pressure at the bottom of the cube?
Since the water from below the cube is also exerting some pressure on the cube
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.
But this prove is for regular body how could we apply archemedis principle for spheres and irregular bodies ?
why didn't we multiply d^2 with g and rho?
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).
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.
when Sal cancelled out those two phg's, I may have been more aroused than I've ever been in my life
Isn't pB also acting downward not upward?
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..
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. 😀
@@Arafat-my6fe thankyou!! I totally forgot about it since it was 2 years ago ahahah
2 years later, I'm in the exact same position. LOLLLL!
Hotel?
Trivago
I'm confused why you never spoke about the force of gravity ?
So straight to a cup of water... no good morning 😂
thanks
sisisisisiis
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, ....
why did he ignored the weight of the cube when calculating the net force ?
Love his videos, but his idea of fun with friends can result in pretty awkward situation
i wonder if you would reply to this
@@brightface5005 I wonder if you would reply to this.
ITS FREAKING 2022 it was 2008 dayum
Buoyant force is the same as upthrust right? Sorry my English isn't that good
Yes
great video, thanks!
i love you.
@reesejpuc I'd go for the sal.
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?
My guy made the video before I was born lmao
Good
Jesus what a mess. Also, i was hoping to understand how pressure actually affects archimedes
The
The voice is very slow
That's interesting
I love you so much.
We have a kid typing
Thats is not a P, please
woah. lol
#flatearthproof
#flatearhclues #flatearthproof
i just dont understand....i am in 6th grade and my mother makes me learn these things....... lol
are you serious?🤣
not what i was looking for mate. Salman can do better