Psi Definition and 169 Threads

  1. Greg Bernhardt

    HVAC Ideas for reducing home boiler PSI

    I have a two-story house with a 30-year-old water boiler rated for a max of 40 PSI. When the system is cold it rests at about 18-20 PSI and when fully hot it sits around 30-32 PSI. I had a tech come and take a look because I read somewhere PSI should be around 15. The tech said my gauge might...
  2. Edm

    B Air tank PSI and cubic feet calculation help please

    If I have a air tank that is 1 cubic feet with the pressure gauge at 0 and I pump in air to 5000 psi how many cubic feet of a 100 psi would be in that tank? Any help would be appreciated
  3. T

    B Concussion question regarding PSI for football helmets

    Hi, I have a bit of a random question which is a little apples to oranges. I saw that concussions on the human brain are caused at roughly 70 to 120 g forces as measured from sensors placed on a football helmet...
  4. philo

    How much pressure in PSI was needed in the Ancient World to cut stones?

    Was watching a video on the the Great Pyramid of Giza and it got me wondering how one might cut one of the stones. Doing a couple google searches, I thought that a Venturi pump would likely be the means by which the stones were cut. The problem being how would they get a large enough psi...
  5. russ_watters

    What is the leakage rate of my underground piping system?

    This is a situation I don't often deal with; I have an underground piping system that is failing a pressure test and losing pressure at a rate of about 1psi/min from 80psi. I'd like to calculate the leakage rate. The pipe is a simple 10" diameter, schedule 40 steel pipe, 500' long (0.365"...
  6. clvsbr

    Programs How to decide between Perimeter Institute’s PSI and Cambridge’s MAST/Part 3?

    Hey guys, I’m gathering information in order to decide which master program to apply to (or, better, which one to go for in case I get admitted to both). I have read quite a lot online but it seems people who talked about PSI took it many years ago, while it was bright new and yet adjusting...
  7. J

    Does Hanging Weight Affect PSI in a Rope?

    Hello; I have a quick question that has me thinking. Please note that i don't much like working with imperial units because there is one too many polysemous words. Say i had a 1 lb weight hanging on a 1in diameter rope. (rope weight neglected) 1. Could you say that at any perpendicular cross...
  8. B

    A Psi function or digamma function?

    Hi everyone, concerning serie representation of psi function. In te solution of bessel function of the second kind we have the following expressions for the psi functions psi(m+1) and psi(n+m+1) then they give the series for the two psi functions ie(or digamma function) sum k from 1 to m of...
  9. bjAndrea

    B Converting 10 PSI to Electrical Energy

    This is not my subject, but I need to know if I can convert 10 PSI to energy. for example, If I have a permanent magnet motor rotate X time (RPM) to produce 10 PSI. Now Can I invert this process, if I have 10 PSI and let it pass on a permanent magnet motor, How much electricity will produce? in...
  10. C

    Converting PSI Pressure Loss in a Pipe to Fluid Loss Rate

    Summary: Pipe Testing I need some help on how to calculate PSI loss to gallons per hour? We will be testing this 8" PVC line at 150 PSI for 4 hours. If the test gauge drops 10 PSI per hour, what is the formula to determine the gallons per hour lost? Thank you for your help.
  11. T

    Equvialence of Gravity Weight and PSI

    I've been searching the web for an answer to my question without success, My question is... Is it possible to equate the gravity weight we experience on Earth with the PSI you would experience in places as deep as the Mariana Trench at 10,994 meters which would approx. equal 16,000psi? ex. Would...
  12. Mads W

    Wood/Glass/Metal Help with the calculations: can a flat steel bar can hold this table?

    Hi everyone! Brand new here. I'm sorry if this isn't the right place to post this but I am terrible with math/calculating anything so I thought I would reach out and ask! No harm done, hopefully. I'm building an 8' x 3' x 2" live edge walnut slab table and am trying to create some steel legs...
  13. MichPod

    I Why protective measurement is important to understand psi?

    Why protective measurement is important to understand whether the wave function is the ontic property of a single particle and not of the ensabmle of similarly prepared particles? I need some help with understanding the following topic (which is currently above my level so I may easily miss...
  14. M

    How long will it take for compressed air to reach 29 psi?

    A large tank filled with air is compressed to 49 PSI. A valve is open and air escapes through the hole (d = 0.04 ft) to the atmosphere. How long will it take for the compressed air to reach 29 PSI. Assume constant temperature. Not exactly sure how to approach this problem since the flow rate...
  15. R

    A Calculating air gun energy vs PSI & bore diameter

    So I'm trying to figure out what kind of energy that I can expect out of a few different setups. Here are the barrel bore diameters. .224 .308 .5 .77 The barrels are usually rifles and some projectiles are full size (size of bore) while others use sabot's where a .224 or .308 can be shot...
  16. S

    Calculating the PSI needed to generate a certain fluid speed

    How much pressure in PSI would it take to generate 150mph stream out of a 2 mm perfectly round orifice? And how many GPM would that equate to? Thanks for any help
  17. D

    Expectation Value of Q in orthonormal basis set Psi

    Homework Statement Suppose that { |ψ1>, |ψ2>,...,|ψn>} is an orthonormal basis set and all of the basis vectors are eigenvectors of the operator Q with Q|ψj> = qj|ψj> for all j = 1...n. A particle is in the state |Φ>. Show that for this particle the expectation value of <Q> is ∑j=1nqj |<Φ|...
  18. SemM

    I How to identify admissible functions in QM by simple math?

    Hi, in QM literature the inadmissible solutions to the Schrödinger eqn are often , if not always, quoted in the text as "inadmissible", because they are discontinuous, not-single valued, not square integrable and not infinitely differentiable. However in a discussion with Dr Du yesterday...
  19. OldWorldBlues

    How do you calculate air pressure in psi from volume?

    Hiya! I'm an ameture "maker", and recently I've become interested in air pressure and such. I thought a fun project to help me learn about it would be to make one of those small air cannons that are powered by bicycle pumps (safety first and all that). One thing confuses me though: how exactly...
  20. J

    B Wave equation, psi with dots and things like that....

    Hi everyone! I'm a psychologist form Brazil, so sorry for the bad English and for the lack of knowledge in math! I ve been trying to understand the Schrodinger equation and, as predicted, it's very hard! Please, help me with this: A sine wave function can be written as: F (x) = sin (x) And...
  21. binbagsss

    Elliptic functions: Weierstrass psi function limit

    Homework Statement Show that ##\lim_{z \to 0} z^2( \psi(z)-\psi(\frac{w_j}{2})) =1## where ##\psi(z)=\frac{1}{z^2}+\sum\limits_{w \in \Omega}' \frac{1}{(z-w)^2}-\frac{1}{w^2}## where ##\Omega## are the periods of ##\psi(z)## Homework Equations The Attempt at a Solution ##\lim_{z \to 0}...
  22. F

    B Understanding the Ontic Nature of Wave Function in Quantum Mechanics

    I'm reading a lot of references about this today.. but I'm kinda confused.. so I need to know some basic to aid in the understanding and able to scrutinize the material. Wave function needs more 3 coordinates to specify a quantum state.. like 6 dimensions for 2 properties (like position and...
  23. single0speed

    Need help on this question for a project i'm making

    I worked out about 7-10psi in the pipe. What do you guys think?
  24. S

    CFM at Different PSI: Understanding Compressed Air Systems

    I have a compressed air system powered by a 25 HP reciprocating compressor giving 109 CFM @ 175 psi. This system also provides air through a ball valve off the main system for vibrators totalling 186 cfm @ 80 psi. Where does all this cfm come from that powers the vibrators when the pressure is...
  25. N

    I Is there a psi ontic Copenhagen interpretation?

    Is there a psi ontic version of the Copenhagen interpretation ( where the wave function is regarded real)? Can the wave function be real in Copenhagen interpretation?
  26. J

    How fast will 120 psi travel through a 3 inch tube in mph?

    I need help finding out how fast 120 psi will travel though a 3 inch tube in mph. My partners are counting on me and thanks to anyone that can help me.
  27. mbewley59

    Sealing a wiring port to withstand water at 130+ psi?

    Hey everyone- I'm designing an ROV thruster which, for starters, will operate down to a depth of 300 feet. My problem is that I can't find any information regarding an electrical port which can pass through the hull out into the pressurized atmosphere without leaking. This will be a 12v system...
  28. MichaelT17

    A box Under Air Pressure -- will it blow?

    Homework Statement I'm doing a personal project to keep me busy for the winter. I grow Bonsai and I'm making a hospital for sick trees or recently collected ones from the wild that need to recover. I have constructed a 40x40 inch plywood box, 5/8 inch thick walls, air tight. The lid will be...
  29. D

    Making a shop press using a electric motor

    I'd like to make a small shop press from an electric motor, say 18'' tall max, with 6" of travel. It should be able to press say 10,000 psi and hold for several second or even maybe indefinitely. My question is two fold. First, what type of mechanical action would be best to turn circular...
  30. T

    Calculating Psi from Rectangular Box Experiment

    We performed an experiment on a rectangular box of measured dimensions made from a certain material. We loaded the box with weights until mechanical failure. So, I know the dimensions of the box and the amount of force put on it until it failed. Would I be able to accurately calculate and...
  31. K

    I Why psi squared instead of psi?

    Why should we square the abs value of the wave function to get probabilities? Why don't just forget the imaginary part, and (in order to get positive values) square the real part of the function?
  32. Nipuna Weerasekara

    B How is the Wave Function Derived in Quantum Mechanics?

    Everybody knows what is the Wave Function is. $$\Psi=\space e^{i(kx-\omega t)}$$ or $$\Psi=\space cos{(kx-\omega t)} \space - \space isin{(kx-\omega t)}$$ But can anyone tell me how it is derived. Since Schrodinger Equation is derived so easily using this Wave Function. I think it is necessary...
  33. H

    I How much force is needed to shatter safety glass?

    Hello, I am curious about how to calculate lbs of force like in those martial arts shows where they measure martial artists and professional mma fighters' punching power, and how it would translate to psi. This is because I saw a man at a youth hostel hit a safety glass on a door and shattered...
  34. S

    I Highly localized initial psi in harmonic well

    Say we start with a wavefunction inside a harmonic potential well, such that the initial ##\psi(x)## is confined to a central region much smaller than the ground state (hence ##V(x)\approx0##).. and the expectation Kinetic Energy is equal to an energy eignenvalue ##E_n## of the system. Starting...
  35. T

    Running 12V 30 psi Pump: My Questions Answered

    So I am try to run this 12V 30 pis pump and it says to run it at 2.2 amps @ 30 psi. When I supply the pump with 12V I get a reading of 1.4 Amps so I don't really know what it means by the 2.2 Amps and the @ 30 psi means. Can anyone tell me what this means? Thanks
  36. S

    Soldering PSI Rating: Connecting Air Tank & Valve

    How much PSI can solder take if used on 1/4" threads to connect a air tank and a valve. I think without the solder it will leak air because the threads aren't perfect and i am using a CO2 tank
  37. SanSan

    How Do You Convert Atmospheric Pressure from Atm to PSI at High Altitudes?

    I have an altitude to psi problem that I can't quite figure out. I know I have to use conversions, but I'm not sure how to set them up. At an altitude of 35,000 ft, atmospheric pressure is less than 0.500 atm. Convert this pressure to pounds per square inch (psi).
  38. B

    How to calculate PSI created in an internal combustion engine

    Hi, working on a project and I need some assistance due to my lack of education in mechanical engineering. With that said I will be as specific as possible. I need to figure out how much PSI is exerted on a piston during the power stroke in an external combustion emgine. I'm not sure how to...
  39. I

    Air Cannon School Project Firing Paper Projectile

    Hey guys building an air cannon for class that shoots a wad of paper from a normal sheet of 8.5/11 paper will be dry. Question is... Is Psi more important or CFM with this light weight projectile? Plan on building from PVC, can do 100psi easy. Plan on using a diaphragm valve with a solenoid for...
  40. T

    PSI required to minimize air mattress displacement

    Hello--can anyone please help me estimate the PSI required in an air mattress to minimize or even prevent displacement if a person, say 220 lbs, walked across it? Mattress material and wall thickness variable. Surface area variable. Also, if scenarios where the person is standing still...
  41. A

    200,000 psi closed Thread response

    Yes I fully understand that the people on this form have all of the schooling , degrees and knowledge that they have accumulated to accomplish all kinds of things. And buy my simple question, I did put on display my complete lack of knowledge in the things pertaining to my question. And you are...
  42. A

    200,000 psi Hydraulic pressure vessel wall thickness?

    I'm Having a part machined with a cylinder shape approximately 14 inches in length with a cylinder hole in the center with a diameter of .930 . I have no idea how thick the cylinder wall needs to be. I have looked up and used hoop stress calculators online but I do not understand if they take...
  43. Indianspirit

    Why does the complex conjugate of psi pop out?

    I just started teaching myself multivariable calculus and I know what the modulus of a complex number is but what is the complex conjugate and why does it pop out when we take the mod square of psi? Like the first minute or two of video... What are complex conjugates, how does one find them...
  44. M

    Operators in Quantum mechanics: can one swap \Psi and \Psi^*

    Homework Statement The demonstration for the momentum operator in Quantum Mechanics goes something like this <v>=\frac{d}{dt}<x>=\frac{d}{dt} \int x \Psi^* \Psi dx and then one ends up with <p>=m<v>=\int \Psi^* (-i \hbar \frac{d}{dx}) Psi dx however, if you swap the congugates you get...
  45. T

    PSI needed to move torpedo (expanding gasses)

    OK, humanities guy here trying to puzzle out some possibilities for a forgotten weapon from 1863. I have an early brass torpedo measuring 72" long and, after boring out the inside, carving some channels in the outside and hollowing out part of the nose, weighs in at 480 lbs (with fuel; 274 lbs...
  46. I

    Max PSI Before a Certain Temperature is Reached

    Greetings all, this is my first post. I'm attempting to solve a problem regarding different octane fuels for a combustion engine and how pressure from a turbo can influence the Auto Ignition Point (Temperature where a fuel can ignite before reaching its proper cylinder position). The items of...
  47. S

    Will Two Water Pumps in Series Output 200 PSI?

    Lets say I have two water pumps that are the same and each can output around 100 psi of water pressure. If I were to connect them in series meaning that the output of 1 goes to the input of the other will the total pressure output at the last water pump be around 200 psi? what if I connect them...
  48. X

    PSI & Buoyancy: Container Air Pressure Effect on Sink/Float

    A question about PSI and buoyancy. How does the air pressure of a container effect whether the container will sink or float? For instance, if two containers of the same mass and area (and the mass of the container itself is negligible), one container is filled with 10psi of air and the other...
  49. U

    Psi Meson Decay Modes: Spin, Parity, Quark Content & More

    Homework Statement (a) Explain spin and parity of mesons (b) State their quark content (c) Draw a feynman diagram of J/psi decay (d) Why doesn't ##\chi## undergo leptonic decay? (e) What is the minimum centre of mass? [/B] Homework EquationsThe Attempt at a Solution Part(a)[/B] Spin is...
  50. O

    Psi question about a hydraulic cylinder

    Homework Statement A hydraulic log splitter with a maximum operating pressure of 3000 psi is powered by a 5 hp hydraulic engine. If the log splitter is capable of generating a maximum nominal force of 10 tons (20000 lb) what is the effective diameter of the hydraulic cylinder? What is the...
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