Pressure Definition and 999 Threads

Hi! I'm a student of pharmaceutical sciences which means that my physics knowledge isn’t that great ahah, if I say a big mistake in the following text, a thousand "sorrys" ahah: So, I am now writing my master thesis and currently I am finishing writing a part where fluid mechanics are...

As we know that liquids(same) at same height exert same pressure because of height difference but as I have a question in which there are some figures In which the (d) part lower part is extended horizontally,so by common sense the pressure in horizontal direction should increase But why at...

We know that pressure at a point in liquid is due weight of water couloum above that point but why does we experience force from downside face of object

One of the things I have yet to come across in the explanation for the expansion of the universe is the effect of light... Most all of the matter we observe out there are stars - fusing nuclei and radiating EM energy in incomprehensible quantities... And this has been happening since the dawn...

I am trying to find the pressure in a ANSI stainless steel pipe with a nominal diameter of 10 in. A slurry of fiberglass and water is flowing through the pipe that has a viscosity of 3.2 centipoise. The flow rate through the pipe is approximately 3000 GPM. How can I figure out the pressure in...

I was measuring the water pressure on my house using a pressure gauge with a hose bib fitting. So I screwed it on and the meter read 120psi. Then I started turning the valve off and the pressure decreased the more I closed the valve. There was no flow downstream of the valve (or anywhere...

Good day I'm trying to calculate the pressure drop in each branch of the following loop ring system I used the following formula to find the pressure drop but i seems that it worked only for the ring, and the branch #2 ( the branch in the middle), the solution given by the professor show...

I need to drive a tractor across and area of soft ground without leaving deep tracks. I tested the ground carrying capacity with car and concluded that 700kg is max load on a 265/70-17 wheel, with 2,2bar tire pressure. (That wheel is 265mm wide, 401mm outer radius, unloaded.) As the ground is...

Summary: Pipe Testing I need some help on how to calculate PSI loss to gallons per hour? We will be testing this 8" PVC line at 150 PSI for 4 hours. If the test gauge drops 10 PSI per hour, what is the formula to determine the gallons per hour lost? Thank you for your help.

Hello. My attempt at the solution is as follows: l = 160m Q= 300 ls-1 R= p2/p1= 6+1.01/1.01 = 6.94 (2dp) d = Unknown Pressure drop = 0.3 Bar 0.3 = 800*160*300^2/6.94*d^5.31 0.3 = 1.152x10^10/6.94*d^5.31 0.3 ( 6.94*d^5.31) = 1.152x10^10 6.94*d^5.31 = 1.152x10^10/0.3 d^5.31 =...

I haven't learned what a monovalent salt is, but through some research, I'm assuming it's when a solute like NaCl dissociates into one of each molecule, so C_solute is equal to C_Na + C_Cl. With that assumption, how do I find C_Na and C_Cl? If I read the question correctly, the sample of red...

The thread title is the title of a recently published paper: https://iopscience.iop.org/article/10.3847/1538-4357/ab32da The paper claims to resolve an ambiguity in "cosmological backreaction" models, which are models that take into account spatial inhomogeneity to derive correction terms to...

Look at the above figure. An overhead view of a car passing a truck on a highway. Air passing between the vehicles flows in a narrower channel and must increase its speed. As the speed of air in that narrow channel increases, the pressure reduces (between the two vehicles). What is the reason...

When using a Boyle's Law Apparatus, pressure applied to the plunger can be calculated by knowing the mass of the object on the plunger and the area of the plunger. P = F/A. The change of pressure inside the cylinder can be calculated using Boyles Law, P1V1 = P2V2 Should the value for the...

If we take a slab of air with cross-sectional area of A and height dz in our atmosphere. Now, what we do is make an argument like this :- Pressure from below must balance both the weight and Pressure from above to keep the slab at rest. ( I have added an attachment for clarification) And...

Why would the pressure at points 1 and 2 be the same? I understand they are at the same elevation and due to Pascal's law should have the same pressure, but isn't water denser than air? So in turn, wouldn't it exert more pressure than air? So then how come despite all the water pushing down on...

I want to ask why is it that we use gauge pressure instead of absolute pressure in CV analysis for momentum conservation of fluids. I did read that because P(atm) would be present everywhere so it won't have a net effect on the CV but it's highly non intuitive as I can't apply force balance on...

Please excuse my ignorance. I work for a Natural gas company and have an issue that needs addressed. When gas comes out of the ground it goes into a piece of equipment that separates the water from the gas. The gas goes into a pipeline and the water is dumped into a tank. We are currently trying...

Once I get the pressure, do I have to multiply times de area that is submerged (in this case it would be 25m^2), or do I take the whole area of the plate, including the part that is not submerged (in this case it would be 30 m^2) Thanks

What's really the difference between pressure and normal stress? Also I know pressure acts normal to a surface from the outside Do normal stress acts from inside? I'm reading bird transport phenomena and this is confusing

The basic barometric formula for calculating atmospheric pressure is (Ph: pressure at height h) = (Pzero: pressure at height zero) x exp(-mgh/kT), where the height h unit is meters, P unit is pascals, m is the mass of an average "air" molecule, g is the acceleration of gravity, k is the...

For a construction I am building, I am stumbling on a rather basic physics question regarding pressure. Let's say I have a cubic bucket of 1m^3 that I place upside down on a water surface. I add a downward force (weight) of say 1000N submerging the bucket under water with the air captured...

Hi, Once someone wrote the following to me in response to my query. My query was somewhat unrelated to it and I don't even have the copy of query anymore. The pressure felt by the piston at any time is the average component of momentum of a gas molecule that is normal to the piston times the...

In one pipeline with pressure P1 area A1 decrease to A2 we want to find P2 in area A2 we have bernoulli equation p1+1/2 ρv^2=p2+1/2ρv^2 with low of conservation of mass A1V1=A2V2 that we can write V2=A1/A2 V1 if we keep in bernouli equation we have P2=P1+1/2V2(1-(A1/A2)^2) my quation is...

1. If a gas is kept at constant pressure of 1 atm & the temp. is raised upto the saturation temprature ( 99.97 C ) and just when Tsat is attained the heat transfer is stopped ( Hin & Hout both are 0 , adiabatic conditions ) . Now # If the adiabatic condition is maintained , then on...

I am using a compressed gas tank to fill an otherwise empty container, The gas tank is around 50bar and the container will be filled to 6bar. If I am using a pressure transducer to determine when the container has been filled to 6bar, can I use the information I gain from it to derive the flow...

Hi All, Recently, I have been struggling to seek a solution for a seemingly simple flow question and try to rationalize my thoughts with mechanical engineering knowledge I have acquired from school but none of them can make me feel comfortable about answering the phenomenon I encountered in...

what does it mean that fluid cannot sustain a force that is tangential to its surface.which surface fluids's surface or container? and what does it mean it cannot withstand shearing stress.what's shearing stress and what does it mean here.and why exert force only in direction perpendicular to...

Hi folks, I think a lot about aeronautics and physics for the purposes of helping people. I stumbled across the idea of vacuum airships as a cheap method of transporting food and water to places where it's unsafe for vehicles, or where there are no roads. We all know it's unconventional and...

For an experiment, I need to pump air into a rocket with varying volumes of water, and thus air. However, I want to keep the pressure the same. Given the amount of air a bicycle pump can pump, the volume of air already in the rocket, and the desired pressure, is it possible to calculate how many...

So as stated, I am calculating the pressure and drag forces on an obstacle, but have trouble with which velocities to take. This is my geometry: http://shrani.si/f/3l/13P/2Tihb3iM/projekt2.png . I am guessing that I have to take pressure just before the obstacle and just after the obstacle and...

Here's how I approached it. We know the total mass of the cloud, it is given. Let's call it 'M'. We can also find out the mass of a single hydrogen atom from its atomic weight. Let's call this 'm'. Then N = M / m is the total number of hydrogen atoms in the cloud. The temperature (T) is given...

I’m designing a subsea sensor that will go to a max depth of 600 m (6 MPa/60 bar). In a simple model, it will be made of a pressure housing cylinder and two end caps, all grade 5 titanium. Some geometry is attached. I’m looking for advice on how to calculate the thickness of the...

I am experimenting with using a radiometer as an approximate indicator of pressure in my homemade high vacuum system, running a small turbo pump. I am interested in the relationship between pressure and vane rotation speed, with light intensity being constant. I have only been able to find...

Here is how I thought about it Consider a surface on which atoms bump into, and if I increase the number of atoms and at the same time allow the surface area to increase as well the pressure is still the same because these atoms occupy have size and thus occupy a certain area , and If they are...

Does the real vacuum pressure/underpressure depends only on the amount of impurities? In the case of theoretical Torricelli vacuum test, when no purities left in the vacuum: Is the vacuum 0Pa at 1m height (with 760mm of Hg) and also the same at 10m height (also with 760mm of Hg) of the test...

I'm programming a game in which I'd like to simulate the real world physics of an attack using primarily medieval style weapons. Think dwarf fortress, but rather than assigning damage numbers we're calculating force or kinetic energy. Getting that much is easy enough since I can find the mass of...

Hello all! Basically I intend to create an environment inside a chamber with variations of CO2 percentages, using electrovalves. The mixing gas is always compressed air + CO2. For example: create a 50% CO2 concentration with a total pressure of 2 Bar. The chamber is closed, and compressed air...

Mass = 0.12kg Initial temp = 500°c = 773K Initial pressure = 0.8 MPa = 800,000 Pa Final volume = 90L R = 287 Jkg^-1K^-1 1) Initial Volume V=mRT/P 0.12 x 287 x 773 / 800,000 = 26,662.12m^3 2) Final Pressure P2 = P1P2^1.2/V2^1.2 800,000 x 26,662.12^1.2 / 90 = 1,816,095,330 Pa = 1,816 MPa 3)...

I think I can eliminate A because the equations depict a linear relationship. Since the gauge pressure is in a linear relationship with the absolute pressure, I would say exactly 2, but the answer is d.

Hi everyone! I am working with the theoretical solid phase diagram of water and I would like to know what negative pressure means. Thank you in advance!

I'm looking for a conceptual understanding of pressure in fluid. According to what I've gathered, in static fluid, the pressure at any point in the fluid depends on the depth within the fluid, because there is more fluid weighing down on an object the deeper into the fluid it is. However, for...

Assuming you could get around the material and engineering problems with anything at high pressures what would happen if you kept pressurizing helium past a super solid state. If the pressures where high enough would you have a similar effect to metallic hydrogen with it behaving as a degenerate...

I once was explained the answer to this question - something about both the air and the object being incompressible. However, for the life of me I cannot seem to reproduce the answer of why we ignore air pressure when doing basic calculations. If it matters, the particular system I'm interested...

I have asked this question on Stack Exchange: SE question. I often encountered this sticker on most motorbikes (especially matic ones) [credit: cintamobil.com]: There, when the tire pressure was measured from cold condition, the tire pressure are same regardless of loadout (29 psi and 33 psi...

Problem Statement: An oil with density 900 kg/m3 and viscosity 0.18 Ns/m2 flows through a circular pipe which inclines upwards at 40° to the horizontal. The length of the pipe is 10 m and the diameter is 6 cm. The fluid pressure at the lower end of the pipe is 350 kPa and the pressure at the...

I have a compressed pure gas at a specific temperature and volume. (T1, V1) It suddenly (adiabatically) expands until it's at ambient pressure and a specific temperature. (P2, T2). Given: T1, V1, T2, and P2, I want to find P1 and V2. There's a great example in wikipedia which is almost...

First off, I'm not a scientist or engineer and I apologize if I don't give a clear description of my question. I'm beginning a personal project and was hoping for some knowledge and assistance. What I'm trying to achieve is to have a spherical object (it will be at least twice as wide as it is...

So, quick disclaimer: i am very young. only 12. i might also misspell some thing or not translate it correctly. i just like physics, so don't expect much. So, i was reading in my science textbook (as a hobby) and it asked to describe some examples, in which i should find out wether the work on...

My best estimate was to find the water height and assume it remains constant when venting the air. I know the initial weights of vapor and liquid ( I know the total mass of substance inside the vessel), so I find the new density of water and vapor and calculate the "new" mass and take the...