Pressure Definition and 999 Threads

Homework Statement Hi there, I am having a theoretical dillema which does not involve a specific problem, rather I am thinking of this scenario in my head and I am not sure how to go about it. I am unsure whether to calculate P2 using the head loss or using the bernoulli equation. Because in...

Hello, I'm having a question regarding the sensors and the techniques in fluid mechanics. Since my skills are amazing in this field, here I'm asking you questions xD I want to measure the air pressure of this tube/pipe (P1,P2,P3). This pipe will be flushed with water and then with compressed...

Hello, This is a real simple question but I am having a hard time to answer it. We have cylinder with outer Radius Ro, Inner Radius Ri. Internal pressure = 0. External pressure = to be find. Material is Nylon. I would like to know: External pressure Po at which the tube/cylinder will go under...

Hey, this is my first time posting and I've been looking everywhere but can't find a decent water model. I hacked a program together to decently simulate water physics, but it's not nearly robust enough for what I need. So, in this world, everything is based on a grid. Any non-wall tile can...

Hi guys, I'm a graduate student and currently doing some research on a packed bed - I want to collect gas data from the headspace of my samples so i thought of building a gas collecting chamber on top of the vessel, where i can take gas measurements using calorimetric gas tubes. I'm not sure...

I solved a fluids problem recently and had a question about the answer. The question was, given a fluid in a rotating cylinder with gravity acting axially, what is the profile of the meniscus. I found the answer, which matched the book's, to be a parabolic meniscus. However, when solving I did...

As a follow-on to this thread, which in turn followed this closed thread, I'm starting a new thread on a related real-world problem. Say I have a 2-liter plastic soda bottle filled partway with water, and pressurized. It has been sitting inverted (with the opening pointed down, and sealed) for...

Specifically, how deep can an enclosed space of a polycarbonate (I'm thinking about strong plastics) material withstand underwater before cracking and breaking. Say a 2 liter bottle

Homework Statement There are two similar atmosphere ISA +30C and ISA tropical Maximum, they have identical: Mean Sea level conditions, same basic shape of temperature profile and same lapse rate in troposphere. The difference is the altitude of the tropopause and hence a different temperature...

I want to calculate the pressure profile inside a cylinder whose initial pressure is less than the outside pressure and has a orifice on its surface to flow air through it. Air is a considered as compressible ideal gas and mass flow rate across a orifice is assumed isentropic. Also the...

Homework Statement I am trying to study for an exam and a section in the book on pressure on a plane is shown in the attached picture. I am trying to understand how equation15.16 was derived. I know normally the line of action is found using moments so this seems to be a short cut but I...

I'm working with data across an airfoil and need some help. We've got Kulite sensor data along 3 chord lengths of a certain NACA airfoil. The case is of an incompressible flow. I need to determine the coefficient of pressure at these sensor locations using total pressure measured and I...

Homework Statement A large 30000 L aquarium is supported by four wood posts at the corners. Each post has a square 6.00 cm x 6.00 cm cross section and is 90.0 cm tall. Take Y=10^10 for wood Homework Equations ΔL = FL/AY F = ma ρ = m/V The Attempt at a Solution So the total area is 0.06 * 0.06...

I have a container that measures 1 cubic foot and is full of water. I have another empty container that is 4.5 feet higher than the empty container. The full container has a fluid outlet on the bottom, and an air inlet on the top. A hose (1 inch diameter, 4.5 feet long) connects the fluid outlet...

I am studying for the MCAT and I got an interesting question from a Kaplan book: 15. A water tower operator is interested in increasing the pressure of a column of water that is applied to a piston. She hopes that increasing the pressure will increase the force being applied to the piston. The...

Hello, I'm having a problem calculating the final pressure before condenser. I'm calculating the pressure that builds up in a system that at the beginning has atmospheric pressure @ T=20C and is introduced with 1 mole/second of CO2(44.01g/mol) @ T=60C and 0.318 mole/second of CH2Cl2(84,93 g/mol)...

A metal whose volume of expansivity is 5 x 10^‐5 K^‐1 and isothermal compressibility of 1.2x10^‐11 Pa^‐1 is at a pressure of 1 x10^5 Pa, volume of 5 litres and a temperature of 20 degrees Celsius undergoes a temperature rise of 12 degrees Celsius and an increase in volume of 0.5 cm^3. Calculate...

I am not familiar with concepts of accelaration field, velocity field, pressure field. I have come up with them in the topic of fluid mechnanics called fluild kinematics. My mathematical background is poor. I would like to learn some information about this concepts. Surely they are mathematical...

Homework Statement A 410kg bluefin tuna rests motionless at a depth of 15m below the ocean's surface. The absolute pressure at this depth is 251,700 Pa. What is the volume of the fish? Homework Equations absolute P=gauge Pressure+atmospheric pressure 1atm=1.03e5Pa P=density x g x height...

My wife has a medical condition where her symptoms are reduced at a higher elevation. I have done some study about the relationship between elevation and atmospheric pressure. My understanding is that the higher the elevation, the lower the atmospheric pressure. Looking at a graph of elevation...

Hello everyone! I want to design a rectangle vacuum chamber (12x12x72) out of 1/2 steel. I would be welding the sides together to form a seal. Would this work? any suggestions on what I could do? Thx! (I not great at this stuff so your help is much appreciated!)

Rather than going off topic in a thread about inviscid fluid in a pipe, I decided to start a new thread. For this thread, I'm wondering about the effect of a ducted propeller operating in the air. Using this NASA article as a guide: https://www.grc.nasa.gov/WWW/K-12/airplane/propanl.html The...

Hello! Is it possible to pressurize a substance and break its bonds? Thanks!

Homework Statement [/B] I am trying to understand why books always point as a fact that hydrostatic force on the bottom of a open liquid filled tank doesn't depend on the force due atmospheric pressure because they these forces cancels each other. Homework Equations [/B] P=[P][/o]+ρgh F=P*A...

Homework Statement A 1m^3 steel cube is to be floated on mercury (specific gravity=13.6). On each side of the cube there is a 5mm clearance. Assume that the container is open to atmospheric pressure at 100kPA. Find the mass of the mercury. Homework Equations P=F/A The Attempt at a Solution I...

I cannot understand why specific volume of a saturated liquid rises when pressure rises, specific volume of saturated vapor reduces when pressure rises. This made me remember buckingham-pi theorem. Is there any equational approach or formulation that show this? Thank you.

Homework Statement Can anyone explain why the pore pressure at C is given by( H1 + z + (h/ H2)(z) ) (y_w) ? Homework EquationsThe Attempt at a Solution Shouldnt it be ( H1 + z + ) (y_w) only ? [/B]

Hi, I am currently working on a project where we use syringes to extrude some viscous materials. I will explain what I am trying to do and I just want to know what size of tubing would be better for me. I have a 10 cc syringe connected to 3/32" tubing with leur lock and at the very end, it is...

Calculate the mass of 78 cm3 of oxygen at room temperature and pressure . Im trying to work out the number of moles and then multiply by 32.

Today I was speaking with a professor and he asked me, regarding fluids, what is pressure. I said force per unit area acting normal to a surface. He then asked what I meant by surface. I wasn't really sure how to respond. He also asked me what surface tension was. I said it is a force per unit...

Homework Statement A manometer is used to measure the pressure of a gas in a tank. The fluid used has a the specific gravity of 0.85, and the manometer column height is 55 cm, as shown in figure 3-20. If the local atmospheric pressure is 96 kPa, determine the absolute pressure within the tank...

I am currently doing a research project in the attenuation of pressure waves. With an focus on dealing with sonic booms the are generated from high speed train tunnels. my experiments involved pressurizing a cylinder then using a rapid release valve allowing the air to escape along a pipe. I...

Homework Statement Given a cross sectional area of A=10cm^2 1kg each of water ( ρ = 1000 kg/m^3 ), olive oil ( ρ = 800 kg/m^3 ), and mercury ( ρ = 13600 kg/m^3 ) are poured, and allowed to settle. What is the pressure at the bottom of the pipe? Homework Equations F=PA P=Po+ρgd The Attempt at...

Hello can someone explain the difference between static and hydrostatic pressure in terms of a water in a glass

So I was playing around with Fluid Pressure and Flow over on PHET animations and noticed something odd. When a fluid with high flow rate is going from a large pipe to a small pipe a lower density increases the pressure. And a higher density lowers the pressure in the narrow part of the pipe. My...

A conceptual problem related to a design I'm working on: If I use a pump to suck air out of the top of a vertical pipe, with the bottom of the pipe in water, I can only make the water rise around 10 metres inside the pipe, if I produce a perfect vacuum. Now let's say the pipe was 100m long and...

Homework Statement A 1.3m×1.3m×1.3m cube of nitrogen gas is at 20∘C and 1.5 atm. Estimate the number of molecules in the cube with a speed between 700 m/s and 1000 m/s. Homework Equations P= (1/3) (N/V) (Mv2rms)The Attempt at a Solution 20oc = 293 K 1.5 atm = 151950 Pa Solving for N N=...

I have a pump running at 400rpm with 8" inlet and outlet with head 30 ft 500 gpm. Now I am planning to reduce the discharge line to 6" . Assuming the flow rate and speed constant the velocity in the pipe will increase. How do I calculate the change in head?

Homework Statement A steam turbine in a small electric power plant is designed to accept 4500 kg of steam at 60 bar and 500oC and exhaust the stem at 10 bar. Part C. In off-peak hours, the power output of the turbine in part a) (100% efficient) is decreased by adjusting a throttling valve...

How is it that once the dew point is reached, moisture continues to condense. What is causing the imbalance of partial water vapor pressure? Does the rise in atmospheric temperature simply pass up the evaporation rate too quickly?

If you have two different containers filled with two different gasses at the same temperature, would they have less pressure when connected to each other? Dalton's law states that each of the gases behave independently when it comes to pressure as they fill the space as if they were the only gas...

Hello all, I am posting this question here in this thread and not the homework thread since it is not a homework problem but something I have been working on myself. Let us imagine a fluid flowing through a pipe, we can measure pipe diameter and fluid velocity. The density of the fluid is also...

Morning all, I am working on a Air Cannon Project and have hit a stumbling block. I am trying to work out what tank pressure and volume I would need to project a 1.4kg mass to 83m/s when it leaves the barrel. The barrel the mass will travel down is 4 meters long and 6inch in diameter, would...

Homework Statement In a lecture demonstration, a professor pulls apart two hemispherical steel shells (diameter D) with ease using their attached handles. She then places them together, pumps out the air to an absolute pressure of p, and hands them to a bodybuilder in the back row to pull...

I'm an empirical sciences student who loves physics. While studying geology I learned that the core of the Earth is considered to be solid and the reason for that is because the pressure is too high. Although according to my calculations g( gravitational field) equals zero and when you go out...

It seems like a simple question, with a simple equation, however, what is force of pressure of a sting of a mosquito on the human skin? Does it possible to evaluate, because I haven't found ANY required data, even though, I have a formula P=F/A

Hi PF! Can someone help me understand how to draw lines of constant pressure in an inviscid flow field, say flow around a cylinder. I am having trouble understanding how to draw these. Any help is greatly appreciated! I ask this question because I am preparing for the Q exam for PhD and one of...

I'm trying to compile a complete list of available humid air density formulas that work with air pressure, temperature and dew point (or RH). If you know any, please advise. Thanks, Robert

I've been wondering how I can find the pressure water exerts on a sphere it's in. As for cyllinders and pyramids, and prisms - the thing is extremely easy - you just take the one formula and put in numbers. What about a situation when we have a sphere whose radius is R, and it's half full with...