Pressure Definition and 999 Threads

Hi there, New to the forum. I decided to come here as I am currently working on a formula that will give me the resulting pressure as a result of an increase in temperature within fixed volume. I have used Charles Law and Boyles law and combined them in a way that gives me this increase...

Homework Statement A sealed has a partition stuck down in water, creating two separate air pockets. The pressure at A is measured to 95 kPa (absolute) and the temperature is 20 C. Find the pressure at B. The Attempt at a Solution Why is the pressure at A not equal to B? Doing U-tube exercises...

A paper in Nature is getting some press, for having calculated "the pressure distribution inside the proton". But the theory behind the calculation seems a little odd. Apparently the data pertains to the scattering of an electron from a quark via the exchange of two photons. But each photon...

Homework Statement A pipe has a square cross section and a width of 2.00 m and is used to transport salt water from the ocean into a desalination plant. If a pump pushing the water into the pipe at a depth of 1.00 m below the surface of the ocean does so with a pressure of 80 kP a, and the...

If Bernoulli's equation P + 1/2ρv2 + ρgh = constant, implying that pressure decreases as velocity increases, and the Venturi effect states that a1v1 = a2v, what resolves this apparent contradiction? The velocity slows as the cross sectional area increases, but a narrower pipe would have greater...

Greetings, I have an experiment that pressurizes a small volume at variable rates. 1, 2, and 3 psi/sec. I am trying to think of a way to reproducibly drop the pressure of the container by a known amount while it is being pressurized. Are there valves for this type of experiment? What are...

A quantity of ideal gas undergoes an expansion that doubles its volume. Does the gas do more work on its surroundings if the expansion is at constant pressure or at constant temperature? The answer in the book says W at constant temperature gives a greater value for the given case. But when I...

I am trying to decipher if an error occurred in a calculation given in this paper. It is understandable that if two compressible fluids of different uniform densities have a common interface (e.g. Figure 1), then to be in equilibrium and supported against gravity, there must be a pressure...

Hello, in some exam questions I've looked at it is stated that the pressure distribution is hydrostatic, even though there is fluid motion. (In these cases the velocity has been constant over the section where the pressure is said to be hydrostatic). Is it really possible to assume that the...

I'm referring to pressure as in atm, pascals and PSI, and energy as in joules or watts. Can pressure be converted to energy in some way? I'm aware of the existence of "pressure energy", which is joules per volume, but it's not what I mean. For example, if a pressure of 100,000 atm is exerted...

We want to know how can we determine the pressure of the liquid at the delivery end of the pump. We have a centrifugal pump and a 2" pipeline at the delivery end. Pump delivery performance as per catalog is 510LPM @20 mtr head to 348LPM @36mtr head. The delivery pipe is connected to a manifold...

Homework Statement Homework EquationsThe Attempt at a Solution I think the pressure that the question is relating is the vapour pressure but I do not understand how that depends on the volume of the water contained in the vessel .Is there a relationship between the two ?

what is the pressure vs distance graph if an ice cube is placed at the origin and the temperature of ice cube is maintained constant anytime,in open air,with a temperature difference of 15 degree celsius between the atmosphere and ice cube at normal atmpospheric pressure?

Using a pump we are cycling water through a capsule with filter media inside; while measuring the flow rate (l/min) and the pressure (psi) going in and the pressure going out. The water is cycled back into the same storage tank. As the flow rate increases the differential pressure should change...

The question goes as follows..: A car driver has an accident and drives into a lake. The car sinks to the bottom. The distance from the car door to the water surface is 10m. The car door is 0.9m wide and 1.3m tall. Assume that the car door can be approximated as a vertical rectangular plate and...

Hello, As you can see in the attached hand drawing+calculation, my question concerns the typical method of evolved gas volume measurement by water displacement in an inverted graduated cylinder or "eudiometer". Once a bubble (cavity to be precise) of gas leaves the end of the tube through...

So for a story I'm writing, there is a character with the ability to absorb force and store it (the force never impacts but its absorption works like pausing a movie). The force can be released (or resumed) through use of a circular space called a "rune". The character can control the size/area...

I was trying to log data inside a vacuum chamber, tried an arduino and a rasperry pi. When reaching -30inHg the devices just stopped working, they powered off, no data in or out and would not work ever again. Why? And no, they did not overheat.

Hi. In water, pressure increases with roughly 1 atm per 10 m depth, yet some divers can reach more than 100 m. Why can humans survive more than 10 times the atmospheric pressure, but will die a horrible death within seconds when released into a vacuum (e.g. outer space, even with oxygen for...

Suppose a cylinder was made. It is the same height as the deepest part of the ocean to the ocean surface - about 11,000 metres and about 1 metre wide. The cylinder was filled with water right to the top and stood on the Earth's surface. A small hole at the bottom of the cyclinder was opened...

If you were trapped inside water tight chamber inside a sinking ship, would you survive all the way to the bottom of the Pacific Ocean? Or would the pressure crush the walls of the chamber at some depth?

Homework Statement Solution: Homework Equations dp/dz = -ρh Pressure varies linearly with the depth. The Attempt at a Solution Firstly, I have calculated the pressure at point B. PB = PA - (0.3m)*(1000kg/m^3)*(9.81m/s^2) PB = 88057 Pa Calculating the pressure at point C. However, my...

Homework Statement The initial state of 0.1 mol of an ideal monatomic gas is P0=32 Pa and v0=8m3. The final state is P1=1 Pa and V1=64m3. Suppose that the gas undergoes a process along a straight line joining these two states with an equation P=aV+b, where a =31/56 and b=255/7. Plot this...

Homework Statement Hello, I have a problem with a quote from a textbook I am currently reading, and it is not strictly a homework problem. It is a part of the book in which authors explain mechanism of sound amplification in human ear, specifically by resonance in ear canal and mechanical...

Wondering if I have a sealed steel tank filled with air and the air temp is 0C and the air pressure in the tank is 0, then heat is applied to the tank - what will the pressure be 100C? At 200C? At 300C? I assume the rate of expansion is constant, but correct me if this is wrong. Thanks.

Homework Statement At the top of a mountain the temperature is -5 degree C and a mercury barometer reads 566 mm, whereas the reading at the foot of the mountain is 749 mm. Homework Equations Assuming a temperature lapse rate of 0.0065 K/m and R = 287 J/kg K, calculate the height of the...

Greetings, I've been thinking about the escape velocity having to be greater than c inside the event horizon for a particle to escape. Since this cannot happen, I picture the matter at the core as an insanely dense ball of atoms. But, could the pressure be so intense that atoms cannot hold such...

Homework Statement I need to design a pressure test that, in one cycle, will simulate the 8000 cycles that a given pressure vessel will undergo. I know the dimensions and material of the vessel, the number of pressure cycles it will undergo, and the max and min working pressures. Homework...

Homework Statement Homework Equations How does atmospheric pressure affects the volume of liquid? What will be the volume of the air bubble at the bottom of the lake? The Attempt at a Solution At the surface, the volume is 6.0cm3. So at the bottom, more pressure will be exerted so it will be...

Hi, I'm trying to determine if a compressed air system has sufficient system to feed a new load The minimum pressure required for existing loads and the current load is 7 bar. In order to determine the pressure at E i did a pressure loss calculation for the following A to B - △P start of pipe...

Hello all, I'm trying to calculate the pressures exerted back on a piston by a working hydraulic fluid in a damper system. I've attached a drawing of the system and the equations I'm using. Essentially the piston motion is restricted by flow through an orifice. I have data for the flow rates...

Net Inlet Pressure Required (NIPR) is an individual pump characteristic, determined by test, of what pressure energy is needed to fill the pump inlet. How to generate the curve of NIPR or how to know NIPR of the pump if I am a pump manufacturer??

Homework Statement An automobile tire is pumped up to a gauge pressure of ##2.0 \times 10^5 ## Pa when the temperature is 27◦ C. What is its gauge pressure after the car has been running on a hot day so that the tire temperature is 77◦ C? Assume that the volume remains fixed and take...

Hello everyone, I am pondering on the airflow around a wing: When air flows over a wing, part of the air goes below the wing and part over the wing. Even when the air is moving, the pressure at a point in space is always isotropic. The pressure on top of the wing is slightly lower than than...

Good day everyone. I have a few question that I would like to confirm. Currently I am doing a project that rinses a plastic pallet. The type of nozzle I am looking at is a 65 degree full cone nozzle. Pressure = 0.7 MPa. Flowrate = 3.88 lpm. Pallet size is 1300mm x 1300mm x 100mm. Q1. Is it...

We are trying to design a new product which uses gas pressures in various ways. We are a little foxed about partial pressures: Imagine a small cylinder; 6in long + 1in in diameter. The cylinder is made from steel. The cylinder is divided into two equal compartments – A and B. Each compartment...

Homework Statement [/B] A 25-cm-diameter, 100-cm-high cylindrical container, (as shown), is partially filled with 75-cm-high liquid (density = 900 kg/m3). Determine the rotational speed at which the liquid will start spilling. Calculate the gauge pressure at the centre of the bottom of the tank...

Homework Statement An organ pipe with one end open and the other closed is operating at one of its resonant frequencies. The open and closed ends are respectively: A. pressure node, pressure node B. pressure node, displacement node C. displacement antinode, pressure node D. displacement node...

Greetings, I am trying to understand how to setup/solve for the pressure drop across an orifice L=3.5in The pipe diameter starts at 1in, then abruptly decreases to 0.5in for the length of the orifice, and abruptly transitions to 1in diameter. (See the attached file for an illustration.)...

Hi. If I fill a glass with water up to the top and close it with a coaster, I can turn it upside down without the coaster falling off and spilling everything. Usually, this is explained with the atmospheric air pressure being bigger than the pressure of the water inside the glass (hence, it...

So the pressure for a canonical ensemble is: P = kbT dZ/dV P = pressure P = -∑pi dEi/dV Z = ∑e-βEi pi is the probability of being in microstate i Ei is the energy of state i β = 1/kbT <E> = U = average energy U = -1/Z dZ/dβ = -d(Ln(Z))/dβ How can the pressure (given above) be derived in...

I still struggle with the interchangeability of pressure and temperature and how they affect the performance of various bits of turbomachinery. Microscopically they're very interconnected, in that the measure of pressure is the result of the confinement of the measure of temperature, however...

Homework Statement A closed hemispherical shell of radius R is filled with fluid at uniform pressure p. The net force of the fluid on the curved portion of the shell is given by:Homework Equations The Attempt at a Solution [/B] I'm not even posting the answers because I'm not looking to get...

Basically what I'm trying to do is calculate the amount of water it would take to generate a given pressure at the water tap. Or to put it more simply I'm trying to figure out where the water line is damaged, well more for fun then actually being practical. The water system is simply a well on...

Hi, I have a vessel/chamber filled partially (25%) with silicon fluid (coefficient of thermal expansion is 0.00096 cm^3/cm^3/ °C) and the rest is filled with nitrogen gas at a certain pressure (P1) and temperature (T1). my question is, how to predict the final pressure (P2) If I increased the...

Homework Statement A uniform star has a mass of M and radius of R,use the hydrostatic equilibrium equation to find its centre pressure. (note: not the minimum centre pressure) Homework Equations $$\frac{dp}{dr}=-\frac{Gm\left(r\right)\rho \left(r\right)}{r^2}[1]$$ The Attempt at a Solution...

Greetings, I have very little experience with fluid dynamics and I was wondering how I can calculate a pressure drop across an abrupt change in diameter of the piping used for water. Any help is appreciated! Thanks!

A smooth flexible tube 1mm in diameter and 1 foot in length holds air at normal / atmospheric pressure (14.7psi). the tube is open at one end. the other end is connected to a tank by an open valve. the tube is peristaltically compressed so all the air in the tube is forced into the tank. the...

I feel like this is easy to answer but I'm coming up with answers I don't trust. Basically, I have a tank of air where I want to keep the pressure at a certain value. Let's say 1 psig for the sake of argument. I have a 1/2" ID hose connecting to inlet flow to the tank and an outlet hose of 3/4"...

Hello, I came across this line in my textbook: "Total peripheral resistance (TPR) increases diastolic pressure more than systolic pressure." I don't understand how the peripheral resistance would increase the diastolic pressure more than the systolic pressure? Could some one explain that...