Process Definition and 1000 Threads

Does Q exist during Constant volume process in Stirling engine? It seems like Q=E=3/2nRT? but I am not quite sure.

Hi, I try to understand the nebular theory (how the solar systems are formed) but I keep having problems with the flattening. My physical intuition "feels" the flattening process should happen, but I want a physical/mathematical qualitative explanation. What is the key physical law that...

Homework Statement Let X(t), -inf< t < inf, be a second order process. Show that it is a second order stationary process if and only if mu(t) sub x is independent of t and r(s,r) sub x depends only on the difference between s and t. Show that is a second order stationary process if and...

hi, so I'm just finishing up my junior year and would like to try to go to grad school for math. I got into an REU program this summer that ends around the beginning of August and plan to start studying for the GRE sometime during the summer. Right now though, I'm a little confused as to how I...

Homework Statement Example 3 in this pdf: http://karin.fq.uh.cu/qct/Tema_04/04.03.Los%20valores%20y%20vectores%20propios%20de%20un%20sistema/Diagonalization.pdf" Homework Equations Gram-schmidt process: v2 perp = v2 - (u1*v2)u1 The Attempt at a Solution I don't understand how they...

Homework Statement 200W of power is required for an isothermal process of a larger cyclic process. Use the first law of thermodynamics to calculate the amount of heat power that is generated by the isothermal process. Homework Equations Change in heat energy = change in internal energy +...

HELP! How to process multiple files in C++ I have been bashing my head against my desk in my cubical trying to figure this out. I have approximately 500 files I would like to read in, one at a time, into a C++ program, do my processing, and send the results to a new file. I can do the...

Homework Statement A frictionless piston cylinder contains ideal gas hydrogen , R = 4.125 KJ/Kg.K , initially at p1=100 Kpa , t1 = 765 C , V1 = 0.35 m3 . The gas undergoes a polytropic process with n = 1.22 until the final volume becomes V2=8.0 m3 Cp = 14.3338 , Cv= 10.2043 ...

1.>Consider a gas in a vessel with a piston on top.Let it expand to a greater volume. So, delta H=delta U+delta(PV) but delta U is 0 as it is isothermal. now,as the number of moles of gas remains constant,delta(PV) is nR(delta T) which is again 0. SO delta H is 0. Thats what my book says...

Consider a quasi-static expansion of a gas. If you change the external force by dFext, then the system will do work on the surroundings until the internal pressure equals the external pressure, right? Now, how does the temperature of the system and the surroundings chnage in the process...

CO2 appears to create global warming, but is there a way to get rid of the CO2? Could we somehow industrialize the photosynthesis process to get rid of large amounts of CO2? What sorts of issues prevent this solution?

1. Assume that earthquakes strike a certain region at random times that are exponentially distributed with mean 1 year. Volcanic eruptions take place at random times that are exponentially distributed with mean 2 years. What is the probability that there will be two earthquakes before the next...

Homework Statement 1. Assume that earthquakes strike a certain region at random times that are exponentially distributed with mean 1 year. Volcanic eruptions take place at random times that are exponentially distributed with mean 2 years. What is the probability that there will be two...

Old topic: https://www.physicsforums.com/showthread.php?t=194725 I have a question that's the same as the one in the old topic/thread I linked to above. At the last post, I am trying to figure out how to carry out the induction process. \sum_{j=1}^n (-1)^{i+j} a_{ij} det(\alpha A_{ij})...

Homework Statement I am just curious whether or not there is a step-by-step algorithm that will always produce the desired results when solving BJT circuits? We are learning them in my electronics course at the moment, and it seems as though the approach to the problems is never...

Hi everyone, My data consists of road accidents and spatial covariates. Originally i wanted to apply an inhomogenous Poisson process with covariates. Then I realized that the accidents cannot occur everywhere in space, but only on roads. I found an example, that is quite similar to mine. it...

Homework Statement Air with the mass of 10kg, with pressure 15 bar and temperature 50 C comes to a isobaric expansion to 3 times the original volume, then the air cools to the pressure of 6 bar(isovolumetricly). After that it comes to adiabatic expansion to original temperature (50 C i guess)...

I have seen a reversible process defined as one in which the system and surroundings are restored to their initial state without change elsewhere. As far as I am aware, the system and the surroundings completely occupy the universe. So, I am failing to understand what elsewhere means in this...

Hi, An amount of ideal gas undergoes the folowing cycle process in the following graph: This process can be presented by the following PV-graph : The answer has to be the upper graph but why can't it be the lower graph ? Thank you!

Homework Statement I have a diagram of a process of a monoatomic gas. and the problem is that I know that the total amount of work = total amount of heat, so there is no internal energy change. why? because my process started at the same temp that it finished. how ever... it is asking me...

how could the process of the kidney's process of reabsorpting the water be simulated through a man made experiment?

Hi, In deriving the equation for adiabats : V^{\gamma}P = C. It is assumed that the work done during the process is W = -P \Delta V. But calculating the work done from V^{\gamma}P = C we obtain: W = \frac{C}{1-\gamma}\left[ V^{1-\gamma}_{f} - V^{1-\gamma}_{i} \right] . Also, i believe to...

I am reviewing material for my thermodynamics class and one of the practice exams says that the change in enthalpy during an isothermal process is equal to zero. This doesn't make any sense to be considering.. \Delta H = \Delta U + PV and since this is an isothermal process.. \Delta U =...

Suppose we have two Gaussian distributions with means A and B. These systems have probability P at time T to be located at X. These are the probability distributions of a simple one-dimensional Wiener process. M=mean P(M,T)=1/sqrt(2*pi*T) * exp(-(X-M)^2/(2*T)) So: P(A...

hello, today I faced a problem with explaining why in anaerobic process the volume of UASB reactor is smaller than volume in CSTR with the same amount of final product - biogas Answer should contain characteristics like: difference in kinetics, concentration, rxn yield. Can anybody explain...

Supercooled water freezes. Is this a spontaneous process?? Homework Statement "one mole of supercooled water at -10degC freezes reversibly to ice at -10degC at constant P of 1500atm. The system is at chemical equilibrium. Assume that ΔH_fusion is independent of temperature. Also assume that...

What is the main different within them process ? Any good web or source can gain more knowledge about them?

Hi, Do anyone know where to get free process simulation software, please, if you know let me know, thanks.

When an electron and a positron annihilate, they typically produce two gamma rays, each of energy mc^2 plus whatever kinetic energy available before annihilation. I was recently told that it is an experimental fact that the electrostatic energy between the electron and the positron does NOT...

Homework Statement Suppose 15.2 g of oxygen (O2) is heated at constant atmospheric pressure from 13.3°C to 148°C. (a) How many moles of oxygen are present? (Take the molar mass of oxygen to be 32.0 g/mol) (b) How much energy is transferred to the oxygen as heat? (The molecules rotate but do...

i can't seem to get something in classical thermodynamics entropy is a state function of a system,that means it only depends on the state of a system not time or path. if i have an irreversible process between state 1 and state 2, and back to state 1, and i want to know the entropy change of...

This is not a homework question. I know the answer to this question I'm just not sure how, from reading the question, I would have known what the question is actually asking. If someone could explain what their thought process is after reading the question, and how it is that you know what the...

Homework Statement One mole of an ideal monatomic gas is taken through the cycle ABCA shown schematically in the diagram. State A has volume 0.0208 m3 and pressure 1.22 × 10 5 Pa, and state C has volume 0.0524 m3 Process CA lies along the 305 ±1 K isotherm. The molar heat capacities for...

Homework Statement A cylinder, A, containing a monatomic ideal gas, is fitted with a frictionless leakfree piston. The axis of the cylinder is oriented vertically, as in the figure below, so that the weight of the piston maintains the gas at a constant pressure P0. The cylinder is linked...

What is the concept behind 'irreversible adiabatic process' ? Why is the expression for work done in this case different from that when it is reversible?

This morning, I was lying on my bed, looking at the bright morning light coming in through the window. The blinds (which are white) were at least half shut, so much of the light was filtered through them. I then stared up at the ceiling, and saw a nebulous patch of green. I shut my eyes, and...

Hi, Radioactive materials will decay to datughter products. in the mean process they emit alpha or beta particles with some energy and then decay to new products. In my problem i am just observing U(238) decay process. I need to find the energy values for each decay and also i need...

Just out of curiosity, is there any quasi-static process that is completely reversible? I think the answer is an obvious no because any quasi-static process experiences a net energy loss but I'd like to know if there are any, possibly something abstract rather then mechanical.

when we have light reflecting off a material, what's going on there? is it something analogous to a gas particle rebounding off a container wall due to Coulomb repulsion? If so, what is it that exerts a force to reverse the photon's momentum perpendicular to the surface it's reflecting off...

Hi all, Sorry if this post is a bit wordy but I've been going round in circles and I thought I'd see if anyone on here can help, it's also my first post so be nice... I've been trying to understand how Newton miscalculated the speed of sound. I know that he thought that the propagation of...

Homework Statement The titleHomework Equations ?The Attempt at a Solution The only ways I know of to calculate heat are dQ = Cp.dT and dQ = Cv.dT for isochoric and isobaric process how would you go about doing it for an isothermal process Also if a system isn't a cycle but it ends up in the...

How could you ensure that an electric battery produced an electric current reversibly? How could you achieve maximum work from an electric battery? I really have no idea how to solve this. Thanks for your help! (Also sorry I first posted this in advanced physics...i don't know how to...

Hi I need help to understand Feynman rules for decay for exams. In past paper there is the following question as whether the following are allowed. cc decays to tau++tau-. From What I can see this is possible via the strong force is this correct? The next is cc decays to cu and cu. From...

Homework Statement An ideal diatomic gas at 75 K is adiabatically compressed to 40% its original volume. What is its final temperature? Homework Equations delta U = Q - W W = the integral of PdV PVgamma = constant U = 5/2nKT = 5/2nRT (diatomic, ideal gas) The Attempt at a Solution...

I was given the following question Which of the reactions on the right are allowed by first-order processes? For those which are not allowed, state one conservation law which is violated. What is a first order process in particle physics? i.e what does first order refer to? What would be...

What exactly is a process corner. Is it actually the corner on the silicon wafer? Why does speed vary in process corners? Is the doping not uniform?

Homework Statement how can I calculate specific heat at constant pressure from mass specific heat and mole mass?

Homework Statement a container with air (M = 29 g/mol, treated as an ideal gas). In the container, we have 2.0 L of the gas with p1 = 1.0 atm at T1 = – 50C. The gas is compressed adiabatically to a final volume of 0.5 L. What is its final pressure? Homework Equations I am really not...

Can anyone help me with understanding what is going on at page 11 of these notes? http://www.chem.utoronto.ca/coursenotes/CHM223/Section%205B%20Fall%202010.pdf Do you get why there is 2 delta Gs? I am really confused with what he was trying to do there? ΔG(37oC) – ΔG(25oC) ≈ – (T – 298)...

Homework Statement One cylinder in the diesel engine of a truck has an initial volume of 600 cm^3. Air is admitted to the cylinder at 35 C and a pressure of 1.0 atm. The piston rod then does 500 J of work to rapidly compress the air. What is the final temperature and volume? I found the final...