If water is in-compressible, how can it be pressurized for pipes, etc? Obviously the weight of a column of water goes up with more height of water added, but how does one come to pressurize a fixed amount of water?
For example the water heaters in homes often have a pressure rating, say 200 psi for example, does that mean there is actually water equivalent to a column of water so many feet high that would exert a pressure of 200 lbs per sq inch on the bottom, sealed inside that tank? It seems incredible to me
>water is incompressible >that has something to do with pressure
are you retarded?
Thomas Long
Pressure affects all inside surfaces of a container. Push water one way, it'll enact that force everywhere else.
Ethan Harris
Your water pressure comes from a nearby water tower. There's a bunch of it about 100 feet up, and it squirts out when you open your tap. It takes electricity to pump it up there, which is why when the power goes out you still have water pressure, at least until your dumb neighbors decide to fill their pool.
Nolan Smith
Yes, there really is pressure inside the water heater equal to so-and-so many feet. Or there would be if it was allowed near the safety limit. Obviously, they're normally operated with a great deal of margin.
Pressure has nothing to do with compressibility. If you have a block of solid steel, the weight of the steel is exerted against its bottommost few inches. Weight divided by its "footprint" is pressure. Steel is pretty incompressible but if the pressure gets too high even steel will flow and the block will start to squash.
How does one pressurize a fixed amount of water? With a piston (or some other type of pump). Neglecting gravity, water transmits the pressure in all directions. Pressure times area is force. That's how hydraulics work. You apply pressure with a small piston moving a long distance. It exerts only a little force because of its small area. Elsewhere, a large piston moves a short distance and lifts your car off the ground.
Jaxon Wright
You can ably pressure to something without it getting compressed or deforming.
If you press two fingers together, its not he compression of your skin that is causing the pressure, its your muscles pushing them together. Its the same with water, the pressure on the water's container comes from what ever is pushing the water, like gravity or a pump.
Adrian Hill
I think this might be helpful for you
pressure is just the density of a force applied (integrated over) to a surface
Water pressure is literally impossible to prove with modern scientific methods. It either happens or it doesn't. There is only one real metric to gauge water pressure, and it involves the Holy Spirit.
Thankfully for those among us blessed with the capacity for scientific thought, we can interpret this Holy Water Pressure. There are those among us who will try to claim that Water Pressure is an objective measurement, but said heathens ignore the influence of the Almighty on how water can flow between systems. I'm literally a drunk and shiptosting at this point, and will summarily accept the punishment, be that is may; whether it is in the form of a "ban" from the nu-male Veeky Forums gods or a legitimate ban for off-topic discussion.
I am not a bod
Christian Rodriguez
Remember that the tank/container/conduit for the water is somewhat elastic.
Aaron Nguyen
It just means there's 200 pounds of force behind the water pushing it.
Think of a block of steel. If you push it into a wall the psi is determined by the surface area touching the wall and how much force you apply. You can apply 200psi to the wall, but the steel block isn't visibly compressing. Water isn't compressible, but force can be applied to it to cause pressure on something else. When you fill a container with 200psi of water pressure then close it off, the water itself isn't applying the pressure inside the container. It is the container's walls applying the pressure at that point. The water actually bends the container when it is put into the container under pressure. The same thing happens when the water is in your home water pipes. The pressure expands the pipes a bit; not very much of course. Your home's water pressure tank has a rubber diaphragm or bladder that expands to help maintain household pressure if you have a water pump. If you have a water tower, it is gravity that maintains the pressure.
Charles Butler
desu this
Parker Miller
the water is in-compressible, but there's air in there too.
Here's an interesting video. The guy uses nothing but water pressure to force metal to take certain shapes until the metal fails. Usually, this would be extremely dangerous, but as he points out if you remove ALL the air from the system it becomes much safer.
Leo Barnes
If you push on water in a sealed container then it will push against the walls of the container and against itself in all directions. If the walls of the container won't yield and the water itself won't yield then the pressure will continue to increase even if nothing is changing in volume. There's still force acting everywhere in every direction, but the force isn't resulting in any volume change.
The water heater will contain the same amount of water no matter how high the pressure gets. Trying to push more water in increases the pressure, but the increasing pressure does not reduce the volume that the water takes up (the definition of incompressibility) so no more water enters the water heater.
Levi Collins
One more thing to think about:
>Be water heater. >Make tank full of water hotter. >Incompressible water expands as it get's hotter. >????? >PRESSURE!
Zachary Rogers
Pressure= Force/Area Compression has nothing to do with this.
Nathaniel Mitchell
Why is the "water is incompressible" meme still taught? It's negligibly compressible in ranges that most people will pressurize water, so it's a fair simplification for many applications. It still compresses. Read up on what a bulk modulus is to learn more.
Michael Sanchez
propagation of dynamical pressure waves through continuous media is an unsolved problem.
Charles Torres
Humans are non-compressible under normal circumstances right?
Put 10,000 people in a tiny room and tell them to stand still. Very few people will be hitting the walls and applying a force on the 'container'. Low pressure.
Put 10,000 people in a tiny room and tell them to start moshing. People will bash into the walls, people will bash into other people, thus bashing them into the walls, and people will bash into chains of people, which also bashes some guy into the walls. Lots of forces happening on the container, thus lots of 'pressure'. Meanwhile our medium is still at a density of 10,000 people per room.
Brandon Harris
>It's negligibly compressible in ranges that most people will pressurize water I think that's why the meme exists.
Hunter Young
>force acting everywhere in every direction
Gravity BTFO
Cameron Murphy
Close, but with something along the lines of the ideal gas law you are talking about changing temperature and not pressure. Pressure is a dependent variable in that situation.
Julian Sullivan
Most people don't account for drag when doing highschool physics projectile problems but people acknowledge that drag exists. High pressure pipelines is actually one of the areas where water compressed to a measurable amount. Pressurizing a pipeline that is completely filled with water:
Let's examine a 30 mile long, 10" subsea transport pipeline:
L = 1.9 e6 in A = 78 in^2 K = 3.39 e5 psi dp = 5000 psi
V0 = L*A = 1.48 e8 in^3
K = - dp / (dV / V0)
dV = - dp * V0 / K = 2.8e4 in^3 or about 121 gallons.
Granted, it's a small amount, roughly about 1.5% of the total volume, but if there's a failure, that water is going somewhere at a high velocity. Before you go "but my middleschool teacher told me it's incompressible" think about how a high pressure is even reached and how a pump even works.
Justin Morris
>but people acknowledge that drag exists I think I understand what you mean better now. I don't know, maybe it's just because you can easily demonstrate how drag works in a classroom. You also need it to explain why a pound of feathers and a pound of lead don't hit the ground at the same time even though the math says they should. Meanwhile in most practical applications you can act like water behaving like a solid when the impact is high enough. You only need to wipe out water skiing or on a 10m platform to appreciate that your candy ass is capable of bouncing on water. That's 200% idle speculation on my part though.
Jackson Long
Geologist here, it is not incompressible. The compressibility of water is very important when calculating pressure of rock units far underground
Just that most experimentation treats it as incompressible because the tiny amount water will compress in surface experiments is irrelevant
Daniel Jackson
Water is not completely incompressible, but it is close enough to incompressable that we generally treat it as such for engineering purposes.
As to your second question, a tank feeling 200psi worth of pressure would be a tank where every square inch of surface area on its inside is experiencing the equivalent of 200 pounds worth of force.
Noah Howard
>admits mistake >excuses >willing to accept punishment faggot.
