Gas Definition and 1000 Threads

In a statistical mechanics book, I learned about the degenerate pressure of a Fermi gas under the non-relativistic regime. By studying the low-temperature limit (T=0), we got degenerate pressure is ##\propto n^{5/3}## (n is the density). And then I was told that in astrophysical objects, the...

V = V(n,P) PV = nc dV = (-cn/P²)dP + (c/P)dn dW = (cn/P)dP - (c)dn This was how i tried to attack the problem, but it will end with log and probably it is wrong, any tips to fix it?

Now this is how I've tried to solve this $$ v_e = u0 \cdot ln \frac {M} {M- μ \cdot t} $$ After putting in the values I get this; $$ v_e = 200 * ln 0,36 $$ $$ v_e = 73,54 \frac m s $$ Now I'd say that this is the correct way to do it, but this part is confusing me "What is the speed of the...

Hello ... I had a question about the capabilities of the two-stage light gas guns which are used to study the effect of small meteors on spacecraft shields ... is it theoretically possible to achieve velocity above 7 km / s for a projectile of about 16 grams weight and 15 mm diameter using a...

Hi folks, Any idea about what is it? I am required to find parts like these items which are made of stainless steel 304 and used on the post-treatment of diesel engine gas.

Is this right for difference between idea gas and perfect gas. trying to get it into head but can't find simple explation.Idea gas it is a fictious matter that follows the PV=nRuT or PV = mRuT equation, which has predermined conditions of ideal conditions of the the gas. As temperature for...

Solution from the textbook: My work: I constantly get 1.55kg. I also tried dividing the first and the second equation (pxV=m/M x R x T with different values). How did they come up with the equation in the solution? Also, I am sorry if I posted it in the wrong place and didn't follow the rules...

In our class, we're using Wassermann's Thermal physics as textbook. I always try to solve all question which included in Text book. But sometime when I meet a problem that look like easy but actually hard, I'm so embarrassed. This problem do also. First, in the textbook grand potential for van...

I have no clue. I am stuck. I would appreciate If someone could help me out. I just know I need to use the Saha equation.

The correct answer is 'C'. I'm having trouble understanding the solution shown on this link (http://www.engineeringadmissionsassessment.com/2019-solutions.html) - scroll down to Section 2, Question 8. From what I've gathered, [final pressure = initial pressure x 'R^3/r^3'], as PV must be...

A cylinder contains an initial volume V1 = 1m^^3 of a perfect gas at initial pressure p1 = 1 bar, confined by a piston that is held in place by a spring. The gas is heated until its volume is doubled and the final pressure is 5 bar. Assuming that the mass of the piston is negligible and that the...

Hi, I didn't understand the maths involved in the below article in regard to temperature and ideal gas thermometer. If any member knows it, may reply me. If triple point of water is fixed at 273.16 K, and experiments show that freezing point of air-saturated water is 273.15 K at 1 atm...

Hi, I tried to do this question in two different approaches one of them was using the equation PV=mRT where I got the right answer which is 4.305 m**2. However, I tried using this Density = Mass/Volume, where I substituted Denisity= 1.225 and Mass equals 5kg to get the volume as 4.08. Can...

The answer given to the above question is Final pressure$=\frac{(10.0mol\times 5.00bar) + (5.00 mol \times 20.0 bar)}{(10.0 mol +5.00 mol)}= 10.0 bar$ Is this answer correct? if yes, How and why? My question is while computing this answer, the volumes of each gas is not considered. Note:-...

I had already found the Mass of the product (C3H3N) produced by this reaction (theoretical mass at 100% yield) in a previous problem. I did this by finding the Limiting Reagent (C3H6) in the reaction , calculating the number of moles of C3H6 and using the Molar Ratios in the balanced reaction...

I ASSUME THAT THE PRESSES OF THE TWO CONTAINERS WILL BE EQUAL IN THE FINAL (STATIONARY REGIME). SO Pa = Pb naRTa/V = nbRTb/V naTa = nbTb Than , I just need to set up a system My question is , so, will the two pressures at the end be the same? And as for the temperatures, can I also say...

##\frac{P_{cylinder}.V_{cylinder}}{P_{balloon}.V_{balloon}}=\frac{n_{cylinder}.R.T}{n_{balloon}.R.T}## ##\frac{n_{cylinder}}{n_{balloon}}=\frac{4 \times 10^4 \times 2.5 \times 10^7}{7.24 \times 10^3 \times 1.85 \times 10^5} \approx 746## But the teacher said I should take the volume of gas...

Normally expansion implies colding, but I don't know how to explain this with the equation of perfect gazes : ##PV=nRT## If V increase then the pressure diminishes. Admitting a constant number of molecules, is the number of shocks is inversely proportional to the volume ? But this only implies...

P1V1=P2V2 (2.5x10^7x4x10^4)/1.85x10^5 , V2 = 5.41x10^6 cm^3 5.41x10^6=4x10^4+7.24x10^3 N N= 741

So essentially you are supposed to find the mass percentage of N2H4 in the Hydrogen/Nitrogen mixtures. The way I understood it, the only way to find the mass percentage of the gasses is to find the mole percentage. Which I got as 25%, based on the fact that the ratio of product gasses to...

According to me a=b cause what I have been learning is R is gas constant and hence it will be same for both. But the solution have says something else. According to them Cp-Cv=R/M where M is the molecular mass of gas. So is the above mentioned formula correct? Do we have to take that M term...

I cleaned the two ovens in our conventional gas stove. They light themselves - trying a few times if the flame doesn't strike and give up if no dice. One of the ovens would strike and light, then go out and try again - clunk pause clunk pause etc. I decided to have a look at the burner unit as I...

I was puzzling over how to solve this and finally peeked at the solution. They used the relevant equation above. I disagree with this though. The problem specifically says “the piston is allowed to slide freely!” This means that we don’t let it happen slowly. So then we are not in...

Hi I have read that the propane gas tank gauges that rely on pressure are useless because as you use the tank part of the liquid propane turns to gas raising the pressure again inside the tank. What id like to know is then how do these gauges work? And also I would like more detail on how...

I have air/gas pressurised gas (pressure is 7 barG). I want to know what are the parameters of the divergent nozzle needed so that the pressurised gas can be released to atmospheric pressure level smoothly and necessary enthalpy conversion can be achieved i.e. the air/gas will accelerate to its...

P1/V1/T1 = P2 V2 /T2 is derived from the ideal gas equation. However it is stated that this equation breaks down at very high pressures and at very low temperatures. Does anyone know what kind of pressures and temperatures we are talking about here?

Up to an undetermined constant ##a## the entropy of an ideal gas goes like$$S = k_B N\ln \left[ a^\frac{3}{2} \left(\frac{V}{N}\right) \left(\frac{E}{N}\right)^{\frac{3}{2}} \right]$$In some notes is written: And then they identify ##\Omega = \left(\frac{\Delta x \Delta p}{w}\right)^{3N}##...

good day! I did not find a suitable forum thread, so I am writing here ... There is a valve through which you need to drive gas under a certain pressure, physically there is no way to drive gas, so it was decided to replace the gas with air. Knowing the required pressure and gas temperature, how...

Working out as follows x= (20-6)/20 = 0.7 Fk = k / air specific heat ratio Fk = 1.31/1.4 Fk = 0.94 xT = Fk * x 0.94 x 0.7 = 0.658 because xT < x = 0.658<0.7 flow through the valve is choked Expansion factor Y Y = 1 - x/( 3 x Fk x xT ) Y= 1- 0.7/( 3 x 0.94 x 0.658) Y = 0.623...

Hello everyone, I was doing some calculations recently regarding particle velocities for different elements at different temperatures and I have a few questions for the experts in here. Usual gas laws in my school book provides information about the velocity of particles in gases, it provides...

I did an exercise about beacons falling radially into black holes from Carroll's book and got a formula for the proper velocity$$ \frac{dr}{d\tau}=-\sqrt{\frac{R_S}{r_\ast}}\sqrt{\frac{r_\ast-r}{r}} $$It's in natural units (##c=1)##, ##r_\ast## is where the beacon is dropped from and ##R_s=2GM##...

Hi, what I've done so far is solving equation 2) for ##U##, and replacing what I get in equation 1). Then, ##c_V## is equal to the partial derivative of ##S## with respect to T times T, so I've done that. The derivative is ##CNR/T##, so ##c_V=CNR## but those aren't the correct units for ##c_V##.

Hi. I am currently doing my internship in the oil and gas industry (contractor) as process engineer. My supervisor give me a task to do some reverse engineering where i need to study how a spreadsheet (calculation) construct by other process engineer was been constructed. Ok the situation is the...

Details to follow if there is interest.

Liquid diamonds apparently may form in gas giants where huge atmospheric pressure compresses carbon into diamonds that are then liquified as they fall downward into zones of increasing pressure. I thought a diamond was a crystal structure of carbon. How can this also be a liquid...

Here is what I did : work done in going from A to C, W1 = 2nRToln(2) (isothermal process) work done in going from C to B, W1 = pΔV = nRΔT = -nRTo (isobaric process) work done in going from B to A, W3 = 0 (isochoric process) so, total work done = W1 + W2 + W3...

I don't know how to approach this problem.

Why do they say temperature is a measure of average kinetic energy how is this possible. how can we take it is it applicable for all types of gases?

Unflued gas appliances emit all of their combustion products into the room in which they are installed. In the UK, ambient carbon dioxide in the commercial workplace is limited to 2800 ppm. The UK/European standard BS EN 13410 (and many appliance manufacturers) give the formula for mechanical...

This isn't right, is it? -\dfrac{GM}{R}+\dfrac12 v^2=-\dfrac{GM}{R+h} v=\sqrt{\dfrac{GM}{R}}\left( 1-\sqrt{\dfrac{R}{R+h}}\right) He's doing energy conservation. The mechanical energy at the Earth's surface is equal to the energy when the speed is 0.

I'm currently programming lots of physics simulators in DHTML, and my next step would be simulating a perfect gas behavior at a molecular point of view, bouncing inside of an HTML canvas. For this reason, I came across "Maxwell-Boltzmann's law of distribution"(for speed, which I only studied...

1. Adiabatic compression (When compressed quickly, there is no heat flow to the environment Q=0) Isochoric with heat loss (The syringe is still compressed, there should be no change in volume) Adiabatic expansion (When the syringe is released, there is work done only) Isochoric with heat gain...

Summary:: Seeking explanation to classical gas - cylinder - piston problem, not the solution. Problem 1.15 from 7th edition of Introduction to Chemical Engineering Thermodynamics by Smith, Van nes and Abbot) Classical problem, given: - gas in a confined cylinder - piston with weight is placed...

Previous of this problem, there was another problem. that is "What is the change in Temperature of van der Waals gas in free expansion?". I got them. It was C_V dT= -aN^2/V^2 dV Then, I got T=T0-aN^2/2VC_V So i knew that the Temperature is decreased by free expansion in adiabatic process. Then I...

I've first calculated the partial pressures of each gas: ##N_2: 0.4\times 7.4\times 10^4=3.0\times 10^4 Nm^{-2}\\## ##O_2: 0.35\times 7.4\times 10^4=2.6\times 10^4 Nm^{-2}\\## ##CO_2: 0.25\times 7.4\times 10^4=1.9\times 10^4 Nm^{-2}\\## From here, I do not know how to continue. Could someone...

Will the available Volume of oxygen gas for use of patients increase when the pressure decreases from 12.4 MPa to 500 KPa? Is using boyle's law the right way to calculate the available volume?

I was reading an introductory text on nuclear models and came across the Fermi Gas model. I understand that the depth of the potential well of the proton should be less than the depth of the potential well of the neutron due to the Coulombic repulsion between the protons. But I did not...

Hi, An irreversible gas expansion is often described in textbooks with a compressed gas in a cylinder pushing up a weight (with mass m) via a hypothetical friction-less and weightless piston. It is said the work done by the gas is equal to -mg × h and from this you can derive the work for a...

Hi Folks, I am exploring using Ultrasonic for LGP tank level measurement. I went through lots of readings, in particular use of SRF02 sensor. But, It's not conclusive. Anyone has been exposed to solving such problem? If yes, kindly share return on your experience. Appreciate!