Gas Definition and 1000 Threads

Homework Statement An ideal monatomic gas has initial pressure Po and occupies initial volume Vo. The gas undergoes an adiabatic expansion in which the volume is doubled. Calculate in terms of Po and Vo a) the final pressure of the gas b) the change in its enthalpy during the...

Homework Statement The pressure in a bulb dropped from 2000 to 1500 mm of mercury in 50 minutes when the contained oxygen leaked through a small hole. The bulb was then evacuated. A mixture of oxygen and another gas of molecular weight 72 in the molar ratio of 1 : 1 at a total pressure of 6000...

Homework Statement A current ## I=0.2 A ## flows in a resistor ##R = 50 Ω## immersed in a rigid adiabatic vessel that contains ##n=3## moles of Helium. The initial temperature of the system is ##T_0 = 27 °C##. The resistor has a mass ## m = 10 g## and specific heat ## c = 0.2 (cal/K)/g ##...

Homework Statement An expandable cylinder has its top connected to a spring of constant 2000 N/m. The cylinder is filled with 5L of gas with the spring relaxed at a pressure of 1 atmosphere and a temperature of 20C. If the lid has a cross-sectional area of 0.01m2 and negligible mass, how high...

I've gone through many posts but haven't really come across something very clear. And on top of it my knowledge of fluid dynamics only extends to compressible fluids. I have a Nitrogen Cylinder Tank, with an exit pressure of 214.7 psia which is blocked by a solenoid valve at a location very...

http://www.fluidmechanics.co.uk/ I have found this by searching net. The inventor claimed that by using a new kind of piston fitted with fins, he achieved almost isothermal compression and greatly reduced the power consumption process. I want to know how much theoretically sound it is.

May I start by saying hello to all and that I have visited the site before, but have yet to create an account until now. With that said, I am having difficulty calculating proper numbers for a project I am designing. Mind you, it has been about seven years since I was in any physics or...

I have been reading about and contemplating the early stages of star formation lately. An interstellar cloud collapses under it's own gravity to form a star. There is much data about what could trigger it, and what happens when the gas heats up or starts fusing. However, i couldn't find...

Hi Guys I´m studying the absorption and emission phenomena of a gas and, according to Kirchhoff "extended" law, for a body at thermodynamic equilibrium, the following statement is true. ελ(T,θ,φ) = Aλ(T, θ,φ). So, if i understood correctly the meaning of this equation, The amount of absorbed...

In the gas industry engineers often have to purge gas pipes. For example, if repair work must be done on a gas line the fuel gas in the system must be removed before work can be done safely. The Institute of Gas Engineers and Managers (IGEM) publication IGE/UP/1 stresses the need to achieve a...

Today, one of my professor was teaching about Circuit Breaker and he explained about SF6 circuit breaker. He told us that SF6 is electronegative gas. But i really didn't understand what is electronegative gas. Please can someone explain in detail. Thanks in advance.!

So I was reading about Tesla's plan for battery swapping. I didn't think that was such a great idea, since you would be leaving behind something that was a good fraction of the cost of the car. Might there be a better way?: So, it's the future: You've been driving around town, and used up...

Homework Statement Homework Equations The Attempt at a Solution I do not know exactly how to start this problem. I would really appreciate it if you could give me some hints. I know that e^ - t/tau=T(t)-Twall/Ti-Twall where tau=m*cp/hA where h=convective heat tr.coeff and T(t) is desired temp...

Homework Statement Here http://imgur.com/a/4LRM6 2. Homework Equations The equation is given int he questionThe Attempt at a Solution gas will stop flowing when the pressure inside the gas is equal to that of the surroundings. I calculated the final mass of gas inside the cube. Then i...

Homework Statement Why doesn't the temperature of a moving jar of gas increase? Homework Equations Average KE is proportional to temperature The Attempt at a Solution This is just an extension of a problem my friend sent me, and I'm stuck on why even though average velocity is increasing...

Homework Statement Using equipartition law, find specific heat of gas containing triatomic linear molecules. Will the result be different if the molecule was non- linear? In what way? Homework Equations According to equipartion theorem, each degree of freedom gets (1/2)kT kinetic energy and...

1. The problem statement, all variables and given/known Mg metal reacts with HCl to produce hydrogen gas. What is the minimum volume of HCl solution (27% by weight) required to produce 12.1 g of H2? Density of HCl solution is 1.14 g/cm3Homework Equations [/B] This question...

Hello, I am currently working on a storage project which allows me to decouple the compressor from the expander of a gas turbine. (see image link below) The reason I use a gas turbine is to reheat the air which was cooled after being compressed. As you can imagine there is a efficiency loss...

Hello i have done tests on Exhaust gas re circulation on my engine test bench and these are the results, i don't know what's wrong? but at 8% loading conditions i am getting some weird results the trendlines in the graph shows an increase in NOx with EGR is there any explanation for this ? thanks

Hi I am not sure if this is the correct forum to post this on, but I guess it can be moved if it is not. I just want to know what methods exists to detect gases in a room. Smoke alarms use ionization or electromagnetic light. What other technologies exist on the market? What technologies are...

Hello. I am having some trouble with a work related problem. I have a GLP tank of 5000 litres capacity, and we actually have a pressure gauge on it measuring that the gas pressure on top of the liquid is above tolerance. Based only on that data, we need to measure the volume that is being taken...

Homework Statement Homework Equations PV = nRT The Attempt at a Solution ##PV^2 = constant## Differentiating both the sides we get , ##V^2dP + 2PVdV = 0 ## Now , using this along with ##PdV+VdP=nRdT## , we get ## PdV = - nRdT ## . Since ##dV## is positive , ##dT## is negative which...

Edit: Eh, sort of changed the question part way though, so if a mod could change the title to "Question regarding gas flow from high to low pressure". Moderator edit: Done I'm about 99% sure I already answered this question for myself but just wanted to make sure my logic was correct, so if...

Hi there, I took the course of quantum mechanics long time ago. From there I learn how to describe an atom with wave function. For example, Hydrogen has the wave function in (spherical coordinates) space. In the book they consider a reduced mass for the nucleus and the only external electron...

Hello, PF! I'm currently brushing up my fluid mechanics and came across some questions while studying the compressible flow of an ideal gas using Bernoulli's equation. First, consider incompressible flow in the following system Neglecting any changes in elevation, the Bernoulli equation for...

Edited: To summarize the below attached jpg file is the formula for work done by a van der waals gas in a isothermal reversible expansion. Is there a way to find the work done by a van der waal gas in a isothermal irreversible expansion? i.e the real gas expands against a constant pressure (in...

Consider an ideal gas following a thermodynamics cycle, represented on a ##P-V## plane. I read that if the cycle is "travelled" clockwise then ##W_{gas, cycle}>0## so the gas does positive work, while if the cycle is "travelled" counterclockwise then ##W_{gas, cycle}<0## but it seems to me that...

Here I want to know how to find the heat interactions of non-ideal gases in the following processes. 1. Isobaric process 2. Isochoric process I know that internal energy U depends on temperature and volume. And the enthalpy depends on temperature and pressure. How calculation of heat...

I was uncertain wether to put this in the general physics forum, but I decided against it. How do length adjustable gas springs(like for example in office chairs)work ? I know how gas springs work and i even have an idea how length adjustable ones could work. Since you hear a "gas flowing...

Homework Statement Calculate the kinetic energy of CO, CO2, and SO3 at 276 K . Homework Equations KE = (3/2) RT KE= (1/2)(mass)(velocity)^2 The Attempt at a Solution [/B] For CO: First attempt: KE=(3/2)(RT)=(3/2)(8.314 J/mol-K)(276K) = 3441.996 -- So that's wrong Second attempt: Relative...

Homework Statement For some gas specific heats for constant pressure and constant volume are calculated. Universal gas constant is R. Find the formula the helps identify the gas. Include only constants and given information. Homework Equations 3. The Attempt at a Solution [/B] Molar specific...

Homework Statement For a gas of N fermions with mass M in 2D in a region of area A in thermal equilibrium at temperature T, we are asked to find ##U/N## in fuction of ##T## and ##a=A/N##. The attempt at a solution I used ##U=\sum(<n_i>\epsilon_i) = \sum(\exp(\beta(\mu-\epsilon_i))\epsilon_i...

Apologize if you feel this question to be so simple and naive. Suppose a chamber is divided by a insulator into two equal volume (V) chambers, . One chamber contains n moles of hot oxygen at temperature T1, the other chamber contains n moles of cold oxygen at temperature T2. If you move the...

Hi. In some statistical approaches (e.g. canonical ensemble), the particles of an ideal gas are non-interacting. Still, it's possible to derive the ideal gas law and other thermodynamic relations. Wikipedia gives an equation for the speed of sound in an ideal gas. How can there be waves in a...

Homework Statement The figure at the bottom shows a cylindrical tank of diameter D with a moveable 3.00-kg circular disk sitting on top. The disk seals in the gas inside but is able to move without friction. The gas inside is at temperature T. The height of the disk is initially at h = 4.00 m...

My dad and I were going to fill up a tractor tire that was very flat. We had two air tanks, a small (~5 gallons) and a large air tank (~10 gallons) which were both filled to the same pressure (~100 PSI). We wanted to pressurize the tractor tire as much as possible with the two tanks, and so my...

Submarines that had lead acid batteries and were depth charged during WW1 or WW2 sometimes produced chlorine gas inside the submarine. Was that because; 1. Broken batteries leaked sulphuric acid into the bilges where sea water with NaCl had accumulated, or; 2. Leaking seawater flooded the...

Homework Statement A large tube filled with an ideal gas at pressure p1 and temperature T1 has a small break in it towards an envirronement at p2, with p1 much larger than p2. What is the flow rate through the hole to the outside of the tube. Homework Equations pv=rT Δh+Δc2/2=δq-δl h1 + c12 =...

I have 1/4" diameter tubing (tightest point prior to valve) leading to a solenoid valve with a 2.5 mm orifice. I am trying to compute how much pressure it would take to move 1 and 2 CFM of 190C air through the valve (to atmosphere). I am using blowers and I don't know if they will be able to...

Homework Statement This is probably a real easy task for most, but I simply CANNOT manage to calculate it, even given the correct answer. I will translate it as best I can and hope I don't phrase it in a way that causes misunderstandings: 12 Moles of an ideal gas go through an Isobaric...

Hello all, I have perused this forum for a while now. I've never signed up because I have nothing to offer you folks. I'm not evan an amateur, I'm just interested in physics. I'm a critical care / flight medic, so my understanding of physics is really, really, really limited. Although, I'm...

Homework Statement A bubble comes from the bottom of the tank of water to the surface and triples in its volume. If the temperature of the tank of water doesn't deppend on the depth what is the depth of the tank that the bubble was at? Homework Equations ##PV=nRT## The Attempt at a Solution...

I just remembered that in my lab from a few months ago, the 12M HCl we used was "evaporating" or producing gas, similar to dry ice in water but no where near as much vapor. I'm just curious, is concentrated HCl usually like that or was the acid contaminated?

Hello all! I am going out on a limb here looking for information as I am unable to find the answers scouring the internet. Essentially I want to know how a person would go about getting a job working with Gas Turbine Tuning and Controls? I've got an engineering background, lots of gas turbine...

Consider the internal energy of a gas and solid (different materials) both at the same temperature, which material has the larger potential energy and why? Do they also both have the same kinetic energy? Finally is the definition of temperature as the average kinetic energy of the particles only...

Hello everyone! I encountered a problem about the specific heat of electronic gas and I do not understand a formula... so the problem says that experimentally it has been shown that the specific heat of the conduction electrons at constant volume in metals depends on...

Homework Statement Pressure drops in welders tank of oxygen gas from p1=150atm to p2=120atm . How much of the gas will be used ? Homework Equations The Attempt at a Solution In my mind the simplest way of looking at this problem is to consider the process isothermal. But then the volume of...

What is the difference between solid-state (SS), semiconductor and gas lasers? I know SS lasers are optically pumped (generally), while semiconductor and gas lasers are electrically pumped (laser diode). The active mediums are also unique. Beyond this though, I'm not entirely sure about any...

Homework Statement A self-gravitating ball of gas suddenly experiences a rapid increase in its pressure to a new value P'. Taking average density of the star to be ρ and radius R, and ignoring gravity altogether, estimate the time scale of expansion of the star. Homework Equations Force=...

Hello here is a schematic of the problem: http://imgur.com/CgcybVT A stream of helium gas will be used to carry aerosolized particles. I am assuming conservation of mass (and mass flow) The mission is to find the exit stream velocity of the gas. For the time being, i am assuming the weight...