Questions tagged [pressure]
This tag is for questions relating to pressure, in the physical sciences, the perpendicular force per unit area, or the stress at a point within a confined fluid.
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Is a Torricellian vacuum a perfect vaccum(devoid of any kind of matter)?
Is a Torricellian vacuum as such in a mercury barometer a perfect vacuum i.e. is it devoid of any kind of matter? If not , then what does it contain and why?
As a 9th grade student , it is mentioned ...
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Could not agree on the correct answer on the following question [closed]
The following question was asked in a national teacher selection examination, and there were opposition based on the fact that the announced key was wrong and it should be changed. The question is ...
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Why is the zeroth law necessary when temperature is simply a derived quantity in the microcanonical ensemble?
The Zero'th Law of Thermodynamics states that : If two systems are in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
Clearly, this introduces an ...
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Deriving the expression for work done by an ideal gas during expansion, $W = -P_{ext}\cdot\Delta V$, using dot product?
I was studying high school-level thermodynamics in chemistry and we were deriving the pressure-volume work done by an ideal gas confined by a frictionless piston. My textbook derived it in this way.
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Is the concept of pressure applicable to liquids & gasses only or solids as well?
I have notice that pressure is spoken of only for liquids and gases but not solids. Am I correct that the equivalent for solids is ...
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How does nitrogen narcosis occur?
I'm confused as to how the partial pressure of nitrogen inhaled from an air tank while scuba diving increases as you descend deeper. Obviously the pressure of the water above you increases the deeper ...
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Find the density of liquid Y
While solving the question, I had some confusion, that we know net pressure at equal depths must be equal in fluids so if we try to equate the pressures at depth of 8cm (instead of the conventional 10 ...
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How does the partial pressure of oxygen relate to its concentration in water?
I've read that the partial pressure of oxygen in water will be the same as the partial pressure of oxygen in the atmosphere, but that the saturation of oxygen in water is dependent on factors like ...
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"Outrunning pressure": Liquid in free-fall
I've checked out related questions and didn't see an answer to my question.
Scenario: Liquid in open-top container, together accelerating downward with magnitude $g$. It was straightforward for me to ...
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What happens when you cool down a now closed container after the water evaporated in a open contained beforehand?
Imagine you heat up water in an open container until enough water vapor diffuses in the air. Then you stop heating the container, close the lid, and you cool it down. What happens next? This is my ...
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What would the theoretical barometric pressure be at the bottom of a canyon that is about 15 miles below Earth's surface?
I'm trying to create a fictional world. I am kicking around the idea of supercritical CO2 lifeforms that live at the bottom of some abyss. I read that supercritical CO2 must be at 88F and 72atm.
I am ...
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Water tower hydro generator? [closed]
$500$ gallons, $100$ feet high, at tank $10$ inch pipe, every $4$ feet a reduction of $2$ inch pipe diameter, ending in $1/4$ inch tubing to jet nozzles, each nozzle would spin an independent ...
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Is an object's pressure on a surface, affected by the type of surface?
Is an object's pressure on a surface, affected by the type of surface. For example, if a chunk of metal gave a pressure of $2800 \ pa$ on a table, would it still give a pressure of $2800$ on dust/sand,...
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Pascal's law further simple proof for students of an high school
Pascal's law states that a force applied on a surface of a fluid is transmitted within the fluid in all directions of the fluid with the same intensity on equal surfaces. Similarly, it can be stated ...
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Filling a tank by gravity from a larger, higher tank
First post. Hopefully somebody might be able to help.
As per the attached picture, we have a diesel generator day tank which is gravity-fed from a larger, higher storage tank. We also have a vent ...
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When a cork is pulled out of a wine bottle, why does the inner end often expand more than the outer end?
When I pull a cork out of a wine bottle, it usually expands slightly in circumference. This makes sense: you want the cork to be slightly compressed relative to its natural diameter when it's inside ...
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Do pressure gradients affect diffusion speed for gases dissolved in liquids (scuba offgassing question)
This question comes from a scuba forum where we are discussing the technical scuba technique of breathing 100% O2 during stops at shallow depths to speed up the offgassing of nitrogen (N2) from body ...
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Cooking by drowning [closed]
Imagine you drop a giant sack full of fish into the sea.
As the sack drowns deeper, the pressure will compress the air inside the sack.
This will make the temperature rise inside the sack.
Is it ...
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Is atmospheric pressure on an object in vertical plane equal to that of horizontal plane? [duplicate]
Suppose there is a cubic object placed at a surface level. Will the atmospheric pressure exerted on the upper surface of it be equal to that of the pressure exerted on its sides?
As far as I know ...
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Why is the weight ignored in buoyant force derivations?
why is it that the weight that the object makes is totally disregarded in these derivations of the buoyant force? Shouldn't that F up be the weight of the water in the top + the weight of the object? ...
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Simple statics: force due to pressure and tension in an equilateral triangle
A rope encloses a compressed two-dimensional gas with pressure $p$. First suppose the gas is constrained to be square (e.g. it's in a square container that can shrink and expand). Let $T_1$ be the ...
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Thermodynamic relation $p$ for a paramagnetic system
I am currently reading up on magnetic systems and the author made mention of the relation to a thermodynamic variable, the pressure.
The pressure $p$ for a system is
$$p = -(\frac{\partial F}{\partial ...
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What is the relationship between the pressure of water and volume collected by a shower?
Consider a showerhead that releases water at a constant flow rate and temperature. What is the relationship between the pressure of water coming out of the shower and the volume of water collected in ...
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What does the discovery of pressure of black holes imply for spacetime thermodynamics?
As far as I know AdS/CFT and spacetime thermodynamics was motivated by the Bekenstein-Hawking Entropy formula of black holes.
Recently however it was discovered that black holes have a pressure as ...
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What makes longitudinal waves work?
I am quite confused by what makes a wavefront that is part of the compression (line A) turn back towards the rarefaction area. Lets say that the sound is propagating left to right in the image:
What ...
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Why are pressure differences so deadly?
The question comes from this video https://www.youtube.com/watch?v=2w-U5wJafhg which details an incident that occurred at the Byford Dolphin Rig https://en.wikipedia.org/wiki/Byford_Dolphin
A group of ...
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How is Newton per meter Cubed related to Newton per meter squared (=Pascal)?
Is there a way to relate $\frac{N}{m^3}$ to $\frac{N}{m^2}$?
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Pressure problem [closed]
I would like to solve the following problem by equating the pressure of the gas to the pressure due the weights, the force and atmosphere summed. How can I do that?
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Why water pressure is higher in the lower stories of a building when one can can open the faucet on the roof story and have the water free fall?
Say a building comprises 7 stories. Imagine also that the upper story has a faucet that leads to the ground (level 0)
Now it is well known (alas for those on the upper stories) that water pressure is ...
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Negative Total Pressure in Ventilation
I was doing my ventilation lab based on an exhaust fan in a tunnel and when I measured the total pressure I got a negative reading ( something to do with the static pressure being greater than the ...
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How much force would the wind of Saturn (1800 Km/hour) exert on my body if i appear on its surface?
Maybe I should have said pressure. I don't know how to measure the exact pressure of the air molecules on my skin, anyways was curious to know this, like what exactly will happen to my body if i ...
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What is the Curie temperature of iron within the Earth's outer core?
According to Wikipedia, Curie temperature is affected by pressure:
https://en.wikipedia.org/wiki/Curie_temperature#Pressure
If my understanding is correct, since the liquid iron in the outer core is ...
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Can someone explain to me using Grahams Law Why $\rm CO_2$ leaks out of a bike Tyre faster than $\rm O_2$? [closed]
Just trying to work out ideal gas to use in this situation for a project
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Hagen Poiseuille's Law for water flowing through a bent tube
Recently, in a chemical engineering class, I was introduced the derivation for the form of the Hagen-Poiseuille equation. We started from the differential equation $- A \frac{dh}{dt} = \frac{\rho g h}{...
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Equilibrium conditions established in the following scenario
If I was to create a setup as demonstrated below, where I have seperated a container into two halves of equal volumes, and in both halves, I half placed a different gas such that the final pressure ...
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What factors determine the suction of an exhaust fan?
What factors determine the suction of an electric exhaust fan used in kitchens?
I thought about fan-speed, voltage, air-pressure, difference in air pressure, circulation.
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Liquid Nitrogen Tank Keeps Venting [closed]
I have an industrial laser cutting machine, which uses liquid nitrogen. Liquid nitrogen is always boiling and the tank periodically vents excess pressure. The tank is at 350PSI. I have been told that ...
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Are we measuring static, dynamic, or total pressure?
Our lab is using a gas driven shock tube and are using piezoelectric sensors to measure the pressure that the shock wave produces. There are three sensors placed near the end of the shock tube, ...
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Sealed container with water with air bubble at the top — Basic hydrostatic principles fail? What is the pressure distribution?
From hydrostatics, it is said that when you have a liquid with no moving parts, the pressure does not vary on any horizontal slice of the liquid. The pressure only varies with depth.
Thinking about ...
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How loud is the Perseus cluster?
The gas near the center of the Perseus cluster exhibits quasiperiodic pressure oscillations that can be interpreted as sound. I found a paper that says that these pressure waves have a wavelength of ...
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Can you syphone water underwater by using outside water pressure?
If you have an underwater bio-sphere; is it possible, with the correct plumbing,to use the deeper outside water pressure to create a perpetual flow of water towards the shallow end where the pressure ...
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How is underwater pressure affected by ice?
Let's say I have a bucket of freshwater exposed to an environment where ice can form (less than 0C, normal atmospheric pressure, etc.). The bucket is on the ground so ice will only form on the top and ...
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Pressure applied by block
Consider a cubical box of dimensions 50x10x30 (cms) denoting lbh respectively . Now if I take the weight of cubical box to be 50 N then what should be the pressure applied by the cubical box on the ...
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What is going to happen if you place a pitot tube on a working syphon?
I was trying to understand the pressure difference across 2 points on a working syphon and came across this youtube video:
https://youtu.be/ofoR4Sgk1b8.
Previously i thought that at any point on a ...
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Is it possible to determine a moment in time when earth's atmosphere is no longer breathable due to the reduction in atmospheric pressure? [duplicate]
If the universe is expanding, the "pressure" of the "vacuum" in space is decreasing, the earths Atmosphere is expanding, atmospheric pressure is decreasing.
Taking into account: ...
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How much do tunnels extend blast waves from explosives?
As was discussed in the comments, I've crossposted this question to here, and am cross-linking them: https://worldbuilding.stackexchange.com/questions/234669/how-much-do-tunnels-extend-blast-waves-...
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With blast injuries, how much of the damage is from rapid decompression? [closed]
If a person or creature suffers a high explosive or low explosive blast, how much of their injuries will be due to the sudden decompression immediately after the shockwave?
Sudden decompression can ...
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Will the relative humidity in a closed container reach 100 % on heating the liquid within it?
If we heat a partially filled closed container with liquid in it, will the relative humidity ever reach 100% (assuming that the vessel is strong enough to hold infinite amount of pressure). I have ...
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Does the rate of pressure build up keep increasing or remain constant when a liquid is heated in a closed container?
Consider a scenario where we are heating a liquid partially filled, in a closed vessel. Assume that we are supplying the thermal energy at a constant rate (which is quite high enough) to the vessel ...
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Surface Tension on Micro and Nano Scales
Dragonflies have holes scattered across the veins of their wings that are hypothesized to allow air to pass through but keep blood in. These holes are typically on the order of a few nanometers. The ...
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