# pressure

1. ### Plasma in a Solenoid

∇p=j×B (eq. 1) K=nI BSolenoid=μnI⇒μK (eq. 2) ∇p=-2p0r/(a2) (eq. 3) Combining these three equations: j=-2p0r/(a2μK) (θ hat direction) Feel like this is too simple and might be missing a step any help would be much appreciated!
2. ### Water Pressure and 2 dimensional motion

$$H = \frac { V^2 - V_0^2 sin \Theta} {-2g}$$ $$H = \frac {V_0^2 sin \Theta} {2g}$$ So, I need to calculate $V_0$ I'm thinking about pressure. $$P = \rho g \Delta h$$ $$\Delta h = h - L sin \Theta$$ $$F_A = P S_A$$ $$F_A = P S_B$$ Dead End here...
3. ### Need stress value of aluminium for project work

Summary: Im not a physics student but I really need to prove that aluminium will not deform 10m underwater Hi Im doing a project of a product which will sink underwater. It will be a sealed cylindrical vessel, length 2m, width 1m, thickness 0.02m. Aluminium 6061t will be used with a yield...
4. ### I Derivation of the change of air pressure with height

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...
5. ### I Gauge pressure in Momentum conservation of fluids.

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...
6. ### I Normal Stress

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
7. ### Fluids doubt

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...
8. ### B Is it possible to calculate pressure without a barometer?

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...
9. ### I Estimating the damage to a material based on force or kinetic energy

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...
10. ### Thermodynamic Systems - Volume, Final Pressure and Final Temperature

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)...
11. ### I Pressure in fluids

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...
12. ### I Basic adiabatic expansion Question

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...
13. ### Understanding the physics behind an elastic sphere

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...
14. ### I Misting system

I am attaching a standard 5/8" garden hose with approximately 70psi pressure to a copper pipe that is capped on the opposite end with mist nozzles mounted periodically along its length. I want the pressure at each mister to be as similar as possible. The hose attaches at the base, a solid line...
15. ### I Gas Law - increasing temperature with constant volume held

I've set up a simple experiment to look at the ideal gas laws. My experiment is relatively simple in that I have a metal tube which is capped on one side. I am then pressurising the tube with air to 100 psi and locking it off. My thought is that as the pressure increased, with volume held...
16. ### Modeling Hydraulic Brake Behavior

Summary: Relation between deformed foil and friction force Good morning everyone, i have a small leaf or steel that is bent from one side by a Pressure of many bars. in front of the leaf there's a rotating disk, separated by the leaf by a small gap. this leaf, as it deforms, wins the gaps and...
17. M

### Thickness of normal and tempered glass for aquarium

Summary: Calculations of glass thickness for aquarium 140cm (length), 55cm (width) and 80cm (height). Scenarios for normal glass and tempered glass. Hi everyone ! I want to ask you for help to calculate how thick (minimum version and save version) should be a glass for aquarium with sizes...
18. ### Show that a tilted free liquid surface undergoes shear stress

i really cant understand the answer of this question, is the question 1.3 in fluid mechanics by Frank ,M White For the triangular element in Fig P1.3, show that a tilted free liquid surface, in contact with an atmosphere at pressure pa, must undergo shear stress and hence begin to flow. i...
19. ### Well-type manometer

A well-type mercury manometer has a well of 0.02m^2 area and a tube of 40mm^2 area. The liquid has a density of 13,534 kg/m^3.Given that the tube is open to the atmosphere and the well is connected to the inert gas manometer was to measure: Calculate the pressure of the inert gas in kN/m^2 if...
20. ### A Decompression of dry air in relation to temperature

I have a problem that i cannot solve despite my best efforts. I do realize not all information here is relevant, but i still included it so you could get the full picture. Imagining we have a cylinder that is filled with dry air (normal air without water vapor) that has a fixed volume of 8,5...
21. ### Filling a long tube by submerging it in fluid

Hi everyone, I'm working on a first-year college assingment and need some help with it. I need to figure out how deep does a tube, initially filled with air, need to be submerged into water in order get fully filled, meaning in order for the air to be fully displaced by water. The tube is 1/2...
22. ### I Pressure in Forces on Submerged Surfaces

Why does the pressure we take into account is the gage pressure and not the absolute pressure? Reading Fundamentals of Momentum Heat and Mass transfer by Welty in chapter 2 it says "the magnitude of the force on the element dA is PgdA ,where Pg is the gage pressure" my question is why the gage...
23. ### Boyle's law problem -- A beaker containing air is pushed upside-down into water...

1. Homework Statement a Basin contains water , a beaker is put upside down to a depth of 3m inside it , if the volume of the beaker is 250 cm^3 . and its C.S area = 200 cm2 calculate the length of the water column which rises inside the baker , supposed that their is no air leakage from the...
24. ### Pressure Waves in an Open Tube

1. Problem Statement: The pressure in an gas tube of length L stretched along the x-axis is given by P(x, t) = Patm + P1(x, t) + P2(x, t) (1) where , P1(x, t) = 20 [P a] sin (−5.9 x − 1300 t ) P2(x, t) = 20 [P a] sin (5.9 x − 1300 t ) One open end of the air tube is at x = 0m. By how much...
25. ### How can I predict the flow rate for a real life water hose?

Hello! I hope you are all doing well! I've been always intrigued by fluid mechanics and decided to try out a quick experiment with my water faucet. After using some equations I found online [1] [2], I plugged a hose to the faucet and let the water run. I filled a 1 quart bowl and recorded the...
26. ### B Need Help Regarding a U Shaped tube problem

my text box says that the pressure at point A is less than pressure at point B Are not they supposed to have same pressure as they are on the same horizontal plane ?
27. ### B Problem regarding manometer

if we use a water manometer we get the pressure of the gas in manometer by using this forumla : Pgas = Patmosphere ± ρgh and if we use the a mercury manometer we use this formula instead : Pgas = Patmosphere ± h and here's my question : why cannot we use the first formula in both of them ...
28. ### B Why is the height of a liquid not affected by the radius of a U-Shaped tube

Why the height of liquid is not affected by the radius of U-Shaped tube . ..my text book says this and it does make sense because if increase the radius of u shaped tube the height of liquid should decrease as the liquids take shape of their container. Edit : I could not make the title longer...
29. ### I Pressure Difference Between the Inside and Outside of a Balloon

Hello all. I have a question about gasses and pressure: Is there a way to calculate how strong a material making up a balloon has to be to withstand a given pressure difference between the inside and outside? In other words, if I have a balloon I need to fill to a pressure of 10atm inside vs...
30. ### Time taken for pressure equalization between two tanks

1. Homework Statement How to calculate time taken (rough approximation) for pressure equalization between two tanks. Both the tanks have same fluid (Air). 2. Homework Equations Rough equilibrium pressure can be achieved by using equations Ptot = (P1V1+P2V2)/Vtot. Thought of using...