Pressure Definition and 999 Threads

Let's say we have a cylinder of volume V1 with a frictionless movable piston and some gas trapped inside with pressure P1 and temperature T1. On top of the piston lay some small pebbles that add weight and essentially create the pressure P1. Also the system is inside a reservoir of water that...

I am looking at pressure in liquids and I am testing my idea. The vertical tube is 100m, the contraption is filled with water. The vertical tube is very thin(maybe 1mm^2 cross section). The area of the base is ~100m^2. Will he top half be launched in the air if suddenly it cracked?- assuming...

When you hold a screwdriver with your hand, a pressure is exerted on it. Does the pressure you exert determine the magnitude of torque in rotating the screwdriver?

Kittel and Kroemer derive the pressure of a statistical state in the following way: They assume a volume compression of a system such that the quantum state of the system is maintained at all times; thus, the entropy ##(\sigma)## is constant in the process of compression. Now let the energy of...

Question From Paper: A hot air balloon has an envelope which has height h = 30 m high (see below). The balloon is always operated with a temperature difference between the heated gas and the atmosphere of 100K. For simplicity, assume that the envelope contains heated air only (that is, ignore...

I must say that I don't have too much background in physics/engineering. I'm experimenting with hydroponics systems and wonder whether it is theoretically possible to achieve the output flow rate multiple times higher than the input flow rate in a bell siphon? I'm not sure, but my intuition says...

TL;DR Summary: Trying to figure out how much water pressure from a pressure washer is allowable on your typical solar panel. Hi, I'm an engineering student and I'm trying to figure out the maximum pressure from the spray of a pressure washer that would be allowable on a solar panel. (I know...

How much pressure does there have to be to cause degeneration of matter into white dwarf or neutron star material? I tried to find this online and all I could get were the Chandrashekar limits on mass of heavenly bodies. Related, but not the same thing. Presumably once this pressure is...

How can we explain the effectiveness of a force in terms of energy and work? For example, a boxer's punch has a similar amount of kinetic energy to a 9x21mm bullet, yet the bullet has far greater penetrating power. From what I understand, this is due to the bullet’s force being applied over a...

Imagine a firetruck with a hoseline attached to the pump. The pump is set to 800kpa with 100kpa loss due to friction in the 30m hoseline so you have 700kpa at the nozzle. What would the pump's gauge read if you disconnected the hoseline? I thought since there is no more resistance, the...

Hello I would like to build a high and ultra high vacuum system And I found a very simple way to do it in the book: "Building scientific apparatus " l But the apparatus in the original is made of glass what is not for me optimal because I don't have the right tools to process them and the glass...

Suppose we have the following balanced equation $$\nu_A A+\nu_B B\rightleftharpoons \nu_C C+\nu_D D,\ \ \ \ \ \Delta G^\circ_{rxn}$$ At equilibrium we have $$Q_{eq}=K_P=\frac{P_C^{\nu_C}P_D^{\nu_D}}{P_A^{\nu_A}P_B^{\nu_B}}=e^{-\Delta G_{rxn}^\circ/RT}$$ What I think I am confused about is...

is a hydrostatic test requierd if head pressure is still up

I am needing to calculate the pressure that concrete will exert on a cylindrical form for an upcoming project. My question is: if the perimeter forming is constructed as a closed band, will the required tensile strength of that band be equivalent to the hydrostatic pressure against the wall...

I came across this problem while studying for my PE exam: I'm not sure what "P_r2" is supposed to represent. Obviously 480 psia is not 697.5 times atmospheric pressure. This is what the table looks like with the "relative pressure" column: How does "relative pressure" relate to the...

The system is closed, and as much blood rises to a certain height, an equal amount descends from the same height, so the two liquid columns create equal but opposite pressures, and their effect on the heart is 'neutralized.' Therefore, if we ignore friction in the blood vessels, it shouldn’t...

Hi. If we wanna train inside a water pool like just play fighting, how much depth that we need to simulate an altitude at 16000-18000 feet? Thank you.

We define ##dA=dU+P_0dV-T_0dS \leq 0##. In my notes it says if you fix pressure and entropy, ##dA=dH##. I don't get this, because at constant T and S, I get ##dA=dU+P_0V##. It seems that somehow, ##P_0=P##. Is this correct, or am I missing something? Second question about this: If ##T_0=T##...

Hello all, I’m looking for some guidance on cleaning a 15 km non-uniform pipeline that alternates between 4" and 6" Schedule 80 sections, with reducers, bends, and a non-barred tee section (P&ID attached for reference). We’ve calculated a total pressure loss of approximately 30 bar at a flow...

I've attached all my work and data table I used to answer the questions but there isn't an answer key so I would like a second opinion.

Let the charge density be $\rho$, radius be $R$, total charge be $Q = \rho \frac{4}{3} \pi R^3$. We know from Gauss's law, $E (r) = \frac{Q r}{4 \pi \epsilon_0 R^3}$. We also know from Maxwell stress tensor $\sigma(r) = \half \epsilon_0 E^2$. We can compute the pressure due to the electric...

I tried 2 ways to solve it but both yielded different answers. i would like to know which is correct and why the other is wrong. thank you. method 1: consider force of each tyre. 5 x 10 = F = 50N. so 4 tyres = 200N = weight method 2: consider the whole car, total pressure = 4x5 = 20. total...

Here is what I did so far. First of all, at ##P_0## (the opposite end of the exit), I supposed ##u_0 = 0##. (Is it correct?) Hence, using Bernoulli's equation for a compressible gas. ##\frac{\gamma}{\gamma -1} \frac{P_0}{\rho_0} = \frac{u^2}{2} + \frac{\gamma}{\gamma -1} \frac{P}{\rho}##...

In thermodynamics we tend to think of pressure as the frequency of collisions with the walls of the container. And we say that the more the collisions the higher the pressure, the less the collisions the lower the pressure. So lets say we have an ideal monoatomic gas enclosed in a cube...

a) ##P=\frac{F}{A}=\frac{\frac{1500\times 9.8}{4}}{180\times 10^{-4}}=2.04 \times 10^{5} Pa## b) Is the pressure in (a) gauge pressure? My answer for (b) is 2.04 x 10 5 + Po where Po is atmospheric pressure c) (i) it will increase since the size of the tire also increases (ii) I am not sure...

[FONT=-apple-system] First of all, where does (1) come from? What is an intuitive explanation for the meaning of ##-\rho g##? ##\partial P/\partial z## is the rate of change of pressure relative to position ##z##. Since we have a negative sign on the rhs, it seems that ##z## is being...

Imagine a projectile with density p, initial velocity v0 and initial stagnation pressure = 0.5p{v0}^2 being fired into the gas chamber with a final gas pressure given by Pg = nkT, for n being the final number density before (at max pressure of gas) and T the corresponding temperature of the gas...

I tried posting this earlier, but being my first time somehow got it in mechanical and I wanted it in thermodynamics so I am reposting here. Sorry for the confusion: Automotive cooling system Not sure if this is an appropriate forum for this question or not, but I will try. Many current...

Automotive cooling system Not sure if this is an appropriate forum for this question or not, but I will try. Many current automotive cooling systems have a system that is completely filled with coolant and no room for air or expansion, other than slight bulging of the hoses, etc. A pressure...

Suppose the speaker has a container into which pressure is pumped, a rod passes through the container with a disk strung on it with one flat side and on the other with a pointed side, will the disk move in any direction under the influence of pressure?

If the surface is heated, air above it will also heat, its temperature will rise. It will cause two processes: while temperature of gas rise, its pressure will also increase, but, also, as the air molecules get more energy, they will go higher from the earh surface, concentartion of the...

Imagine we have a cylinder filled with water with a closing mechanism, the height of the cylinder is quite large to create increased pressure at the very bottom. If the mechanism closes a small part at the bottom of the cylinder, will the pressure decrease or not? Thanks in advance for the answer

will the hydrostatic pressure be the same on the vessels shown with a different diameter of 1 meter and 1 centimeter? and will it be the same in both vessels if the first pipe has a diameter even less than 1 millimeter, 1 thousandth of a millimeter, 1 atom?

Philosophically, it is impossible to prove a negative, so I will turn to one of the most recognised authorities, Anderson, J. D. (2011) "Fundamentals of Aerodynamics" Fifth Edition. An on-line version can be borrowed from archiv.org at Fundamentals of aerodynamics : Anderson, John D., Jr. (John...

I'm trying to think of the least creepy reason I found my small lateral bathroom window closed this morning. I live in a 2 bed/1 bath apartment on the ground level with my two dogs and no one else. I rarely have people over. My bathroom doesn't have a fan and I don't have the best memory, so I...

I think this problem is somehow weird since fluid has different pressures at different depths.

Hi Physics Forum Folks! What an amazing resource of knowledge, ... thanks! The question is on the attached graphic, as its much more clear with an illustration. (Please read questions on this graphics first before looking at the video below,) This video is a very quick look at the actual...

This is what I thought was a simple task, but it's causing me headaches. I have a conical steel tank with approximately 14 liters of fluid capacity. I need to determine the volume of water in the tank when in use, and we are currently planning to measure the pressure at the bottom of the tank...

please refer below attached file for further details

Hey guys, It‘s been a few years since I had my last physics class so please be kind to me. I came here to ask you about a phenomenon I recently discovered in a design of mine. The object in question is a stand with 3 arms, holding a water tank (see pic below). All openings are pretty tightly...

For a volume fixed in space with the positive component of the z axis pointing up, I have the force of gravity pointing down. Using the following equation I have to derive the Euler's equation. ##\frac{d}{dt} (\rho \vec{u} \otimes \vec{u}) = \phi + F_v + F_s## Where ##\phi## is the flux...

I have found the answers for T = 848.615K, P = 126137.7705 Pa and change in S = -184.27008 J/K. But my answer for work is not correct and I am not sure where I am making an error. Could someone please help me out with how to calculate work? My steps for work is : We are given: Pi = 101325 Pa Pf...

Could line "b" become choked if the diameter at point 3 was increased? If so, what is the limit for the diameter and angle of the divergent section of the nozzle? Is there a point at which the angle is too great, and the diverging part is no longer effective, and the flow goes back to behaving...

A diffuser normally decreases the velocity by increasing the area. With assumption of an incrompressible flow, according to Bernoulli, the static pressure increases. What happens if one "forces" the flow through a diffuser by applying a bigger pressure on the inlet than on the outlet?

Diagram Integrate pressure for each particle: Add normal force and weight Sum all the forces in the x and y direction to get:

I do not remember the correct terms to look this information up on Google. I once read that as a pressure wave goes down into a closed cone every time cross sectional smaller by 1/2 the pressure wave doubles. My cone is 12" x 12" on the open end and 1"x1" on the closed end. Cone is 24" long...

How did you find PF?: Friend I need to move a 2000 pound weight up twenty feet into the air on top of an eight inch diameter piston (surface area of 50 square inches) how much steady pressure would i need to achieve this and overcome the friction on the piston itself. Im trying to lift a door/wall

I had a question today as a part of my studies which was 1) If space is ever expanding what is the pressure on the creating space (universe) upon creation and 2) at what rate might you assume the quantum field is also being created and is it being affected by this pressure of creation. This is...