Pressure Definition and 999 Threads

The Clausius-Clapeyron formula is given by \frac{d P}{d T} = \frac{L}{T \Delta V} where P and T are the pressure and temperature at the boiling point, respectively, and L is the latent heat per mole at the boiling point, and \Delta V is the change in the volume per mole between the gas and...

Homework Statement A vessel having a volume ##V## initially contains ##N## atoms of dilute (ideal) helium gas in thermal equilibrium with the surroundings at a temperature ##T##, with initial pressure ##P_{i} (T ,V ) = \frac{NRT}{V}## . After some time, a number of helium atoms adhere to the...

I am discussing with my friends to see which way is the best way to get the most stable branch outputs when one branch condition changed suddenly. There are three liquid flow branches, A, B and C, connected together with one pressure source, like this configuration: The Water Pump, #1...

Homework Statement A zeppelin of an ellipsoid shape (a=32m, b=c=a/3) iz filled with hydrogen. Pressure of the surrounding air is 100 000 Pa. Temperature of air and hydrogen is 20°C. The mass of an empty (not filled with hydrogen) zeppelin is 10 000 kg. What does the pressure of hydrogen inside...

My text (Ian Ford - Statistical physics) describes an ideal gas system in a piston being quasistatically compressed by a piston head of area A under external force f. It assumes the system has a uniform pressure p. All good so far. Then it says: "the force pA equals the applied external force f"...

Homework Statement An ideal gas has a molar mass of 40 g and a density of 1.2 kg m-3 at 80°C. What is its pressure at that temperature? Homework Equations PV=nRT R constant= 8.314 n= number of moles T= tempreture in kelvin density=Mass/ Volume The Attempt at a Solution i simply solved it like...

Consider a conventional U-tube with both the vertical tubes having the same uniform cross section area A and the horizontal tube of length L, connecting those tubes containing an ideal liquid. Now the free surfaces in both the vertical tubes will be at the same height and will have pressure...

Hello to all Can we consider the core of the Earth to be a superconductor ,for example Aragon national laboratory hinted for some thing like that https://www.anl.gov/article/nickel-for-thought-compound-shows-potential-for-hightemperature-superconductivity That been said , what test could...

Consider a fixed horizontal tube of uniform cross section with pressure being 1atm at one of it's end and 5atm at the other (former due to 'open to atmosphere' and latter due to force on a piston), then liquid would flow towards low pressure end. By equation of continuity all cross sections will...

Hello all, I'm new to this forum and I'm mucking about with some self-made physics conundrums, and I need some help! So, What I am aiming for is a roughly cylindrical vessel (it can, and I think probably has to, be tapered to achieve the effect) with the air being pumped out of one end, and a...

Assuming laminar viscous (meaning not frictionless) flow. Here is what I know about fluids flowing: You have a pressure difference between the two ends of the pipe. This causes a net force acting on the left side of the fluid in the pipe. Therefore, this incompressible fluid flows from left to...

Homework Statement The average pressure of the blood in a person’s arteries is 100 mmHg. What is the average pressure in an artery in the head of standing person 40 cm above the heart? (blood density= 1.05x103 kg/m3,Mercury density = 13.6x103 kg/m3 and g=10 m/s2) Homework EquationsThe...

I keep seeing a popular question asking about atmospheric pressure "crushing" us. The word "crush" throws me off. It is my understanding that air molecules create pressure due to collisions. In other words, the molecules exert pressure due to having kinetic energy - and the more molecules you...

Homework Statement [/B] dp/dh = -.13*p h in kilometers I should convert it into meters2. The attempt at a solution I thought it would be enough to multiply -0.13 by 1000. :( dp/dh = -130*p but it is wrong.

Hi everyone, I have been mulling over the relationship between pressure and boiling for some time, and I am still slightly confused. I shall attempt to provide an overview of my current understanding in the hope that I can get some corrections/clarification on my current conceptual...

Suppose there is a circle with area 'A' and on one of the faces of the circle a force of 100N is applied and on the other face a 30N force is applied (since all 2D surfaces have 2 faces) such that these forces are opposite to each other, perpendicular to the faces, and forces are equally...

Homework Statement The volume and dimensions of the cylinder are given, and the air is supplied to the cylinder at 4 bar at room temperature.Is there a way to find out the time it takes for the air pressure in the cylinder to increase to 4 bar? Homework EquationsThe Attempt at a Solution From...

How much Hp/Kw required to move 1.5L/m of Diesel fuel at 17.2 Bar? Please note this is for a real life problem.

Homework Statement A light source radiates a sinusoidal electromagnetic wave uniformly in all directions. This wave exerts an average pressure p on a perfectly reflecting surface a distance R away from it. What average pressure (in terms of p) would this wave exert on a perfectly absorbing...

At sea level, we experience an external force pressing down on us at any given time which is equal to about 15 pounds per square inch. Pressure is defined as: ##P = \frac{Force}{Area}## where Force is equal to mass x acceleration. When we say that we experience this 15 pounds per square inch of...

Hi! Given that the chamber is airtight and no air leakage occurs, is the design in the picture below possible? Can the pressure inside the chamber cause the button (black part at the top) to be "pushed"? https://imgur.com/a/wOSD30D Obviously the temperatures are over-exaggerated, but the...

Hi I was in a discussion with some friends a couple of days ago. The discussion revolved the pressure raise in a liquid filled container. The question was, is the pressure behavior dependent on whether the container is filled with only water or filled 50/50 water/air. (The discussion started...

Hey, I'm designing an HVAC system for a laundry building. I have vacuum equipment (Vacuum press and Vacuum Ironing boards ) in the space which have a vacuum outlet the is taken outside the building through individual ducts. When all machines are operational, 877 l/s of hot air and moisture would...

So I've been discussing this problem with my plumber dad. I uploaded the picture. I'm wondering if the pressure would change in the red pipe since the diameter decreases to 4 cm. Assume the 1st 10 cm pipe is full with water. Question: If the home pressure is 517 kPa going through first pipe...

I have a 110 PSI pneumatic line. I have a 700 lbs linear force output. I have 1.230" outside diameter spring using 0.250" wire. My 110 PSI pneumatic line with cylinder is able to compress my 1.230" OD spring with 0.250" wire to 700 lbs linear force. My calculations reflect I should require...

Hi. Is there any way to calculate airflow out of a tube (into atmosphere) with only the pressure and cross sectional area of the tube?

hello everybody does always phase undergoes transition when a pressure applied on a crystal ?even when the temperature is constant? and can pressure be increased without increasing temperature for a crystal? best regards Nawzad

At work, we have a cylindrical tank that holds water. The tank is 5 feet round and about 6 feet long putting the highest part of the tank at about 6 feet off the ground. The tank holds 1000 gallons of water. There is a valve on the bottom that I am needing to test and I can’t seem to find a...

Homework Statement A 30kg pallet falls from a height of 2m onto a protective cover. The cover has an area of 269m² and an overall thickness of 10.9mm. a. What is the force/pressure on the cover? b. What is the bending stress on the cover? Homework Equations F=ma bending stress =...

I have been reading the book "Nanostructures and Nanomaterials" by G. Cao and Y. Yang, and was intrigued by the following passage in page 33: "Assuming the vapor of solid phase obeys the ideal gas law, for the flat surface one can easily arrive at: μv − μ∞ = −kTlnP∞, where μv is the chemical...

Homework Statement Find the flow rate of water. The fluid in the manometer is mercury. ##d_{1},d_{2}## are the diameters in the figure Homework Equations Bernoulli, continuity equations The Attempt at a Solution We know that ##p_{1}=p_{1Top}+\rho_{water}gh_{2}##...

My teacher say: Comparisons between the pressure of an object on the inclined plane and the gravity of the object But idk what is sin and cos means I need help THANKS from: vietnam

Hi My question is related to interpretation of temperature and pressure in gases on the basis of kinetic molecular theory. According to it, both temperature and pressure are proportional to average translational kinetic energy of the gas molecules. Now in a situation where an ideal gas in...

Is the force that accelerates afluid betwen two points of different pressure conservative?

Imagine you have a vertical pressure head 2m tall with water flowing down to height 0m and emptying. Through this length we have 3 identical tubes of resistance R and length L. Assuming I know the volumetric flow rate(Q) as a function of height, how can I calculate the resistance of each tube...

Dear all, I have a headache and I need you help, with the following problem. I need to create excel sheet for the calculation (estimate) of the size of the orifice on the orifice plate that will produce a pressure reduction rate in pipeline at 0,5 bar per minute. It is not important to...

Why isn't it called deltaP *delta V work? Or deltaP*V work? Does the expression mean that P is constant while V changes and also what is an example of that? thanks for any help

Hello, I want to develop a pressure regulator model in simscape. The model will be the springloaded direct acting system and the aim is to target outlet pressure, temperature and flow rate by giving input parameters as pressure, temperature, spring stiffness, length and preload, lever(it is...

Homework Statement A spherical hand-held pump with a radius r is used to pump air into a cube with a length L. The pump and cube are connected together by rubber tubing. Express the pressure stored in the box as a function of the number of times the pump is fully squeezed. Imagine the...

Homework Statement A two litre sealed container is filled with air at atmospheric pressure. It is connected to a vacuum pump which can pump air at a flow rate that is proportional to the difference in pressure within the container to the pressure outside. This tells us that the pressure drops...

Homework Statement (In the attachment)There is two layers of liquids in the container .The density of the upper layer of the container, ##ρ_1=800kg/m^3## and the density of the bottom layer of the container ,##ρ_2=13600kg/m^3## .What is the pressure at the bottom of the container? Homework...

Homework Statement I don't understand why the pressure before the construction of foundation is given by (2.5)(16.5) + (0.5)(17.5-9.81) +(1.25)(16-9.81) only ?. Why the pressure is taken only to the half of the layer of clay only ? Homework EquationsThe Attempt at a Solution I think it's...

Hi, This is my first post on the PhysicsFormus I am trying to design an inlet and outlet for an axial fan and calculate velocity and pressure profiles in the duct. See the sketch attached. The ultimate goal is to carry out a CFD study but I was wondering if there is an analytical solution for...

I am trying to find peak pressure of a diesel engine injection pump.. It doesn't have to be exact but +/- 1000psi would be fine. The basic principle is the same as an engine. Piston goes up and covers a fill hole, once it is covered the only way it can flow fuel is through the injector, so...

HI All, I have been out of education a long time and am now back at college. One of my modules is Fluid Dynamics and I am beginning to struggle with the basics and could really use your help. I have attached a snip from one of the example questions below given to me by my lecturer. For part...

Homework Statement An adiabatic isolated system is formed of three identical balloons (of unknown volume). The balloons are joined by tubes of negligible volume. Each tube has a faucet/tap that is initially closed. The balloons have different quantities of the same ideal gas. After opening...

Hello, A silly question I'm sure, if a projectile moving at 13.59 m/s with a KE = 527.47 J hits an area of 3 cm^2, what is the force transfer to that area and the resultant pressure applied expressed in Pascals? Do I divide the KE by a volume instead of area to Pa?

Hello all, I am an Electronics Engineer, working in an R&D Organisation specializing in Electronics and Advanced Computing. My area of work is Control & Instrumentation related to Industrial Automation. I am trying to identify the a solenoid valve to be used on a 2" pipe. For this I need to...

Hello Everyone, I've been trying to find an answer to this but am not getting anywhere. Any help would be greatly appreciated! I need to be able to calculate (or more likely estimate) the pressure drop I can expect when putting water under pressure if I know there is air in the system. For...

I was thinking about how much propulsion you could get out of a solar sail, so I just did a rough calculation: A solar sail 100m*100m in size (10'000m²), with 20grams of weight per m², an additional 100kg for probe and other stuff, so 300kg probe weight. Using the solar constant of 1400W/m²...