> Ok, so, it’s the same as before, but the outlet of the spout is now significantly deeper / lower. So the speed of the water should be higher, right?
> Ok, but if the water is faster at the bottom of the long spout… We could view the top part of this system as an exact copy of the short-spout version. At the interface between the tank bottom and the pipe-spout, the velocity of the water should be the same as in the no-pipe version, right? But that means the water inside the pipe is accelerating inside the pipe:
No, it's not the exact same. In the top part of the long-spout system there's a lack of airpressure holding the water above it back compared to the short-spout, and quite a bit of cohesion in the water pulling the water above it down faster if the lack of air pressure isn't enough. The water in the whole system moves faster as a result.
You'd theoretically get the air (actually vacuum) bubble if you ran the experiment in a vacuum with a liquid that has no cohesion... liquids with no cohesion are otherwise known as gasses though and behave differently in other ways as well.
Oh sorry that was a joke. (Though you could teach that in kindergarten.) When I was in undergrad I had the privilege of taking Laszlo Babai's combinatorics class. I don't recall exactly how he phrased it, but he would say things like "As everyone learns in kindergarten, the powerset of [n] has size 2^n.".
Sigh, thanks for letting me know. Ok since this is the ~third time someone has said this, I'll try to figure out a convenient solution (I guess hosting images on github?). Just FYI a VPN should let you see imgur images.
> in case someone wants to get nerdsniped https://github.com/kamilazdybal/fluid-toolbox
> Ok, so, it’s the same as before, but the outlet of the spout is now significantly deeper / lower. So the speed of the water should be higher, right?
> Ok, but if the water is faster at the bottom of the long spout… We could view the top part of this system as an exact copy of the short-spout version. At the interface between the tank bottom and the pipe-spout, the velocity of the water should be the same as in the no-pipe version, right? But that means the water inside the pipe is accelerating inside the pipe:
No, it's not the exact same. In the top part of the long-spout system there's a lack of airpressure holding the water above it back compared to the short-spout, and quite a bit of cohesion in the water pulling the water above it down faster if the lack of air pressure isn't enough. The water in the whole system moves faster as a result.
You'd theoretically get the air (actually vacuum) bubble if you ran the experiment in a vacuum with a liquid that has no cohesion... liquids with no cohesion are otherwise known as gasses though and behave differently in other ways as well.
Ohhh, oops, good point, thanks.
> As everyone learns in kindergarten, the speed at which water comes out of a spout in a tank depends on the height
What kindergarten did you go to? Maybe my public kindergarten education was seriously lacking.
Oh sorry that was a joke. (Though you could teach that in kindergarten.) When I was in undergrad I had the privilege of taking Laszlo Babai's combinatorics class. I don't recall exactly how he phrased it, but he would say things like "As everyone learns in kindergarten, the powerset of [n] has size 2^n.".
Oh my bad, good article though.
Really nice to see the process of thinking it through. This sort of thing gives a much better insight than just memorizing formulas.
Unfortunately nobody in the UK can see the images in the blog, 'cause imgur
Sigh, thanks for letting me know. Ok since this is the ~third time someone has said this, I'll try to figure out a convenient solution (I guess hosting images on github?). Just FYI a VPN should let you see imgur images.
Thankyou :)