Adiabatic Definition and 470 Threads

I have been asked to show that if an ideal gas is compressed isothermally its compressibility is 1/P whereas if the same gas is compressed adiabatically its compressibility is 1/yP Where y is gamma I have managed to do the first bit about isothermal compressibility, but cannot work out...

Homework Statement 4 liters of an ideal diatomic gas are compressed in a cilinder. In a closed process, the following steps are taken : 1) Initial state : p_1 = 1 atm = 1.013*10^5 N/m^2 and : T_1 = 300 K 2) Isochoric proces resulting in : p_2 = 3.p_1 3) Adiabatic expansion resulting in...

Homework Statement I'm in a rutt for a tutorial question: The question is basically to show that the work done during a reversible adiabatic expansion of an ideal gas is W = (P1V1 – P2V2)/(1 ‐ γ) ... Y is gamma Homework Equations The Attempt at a Solution I've got so...

I'm having a hell of a time understanding this. Can anyone give me a hand? How is it derived? etc?

As the title says. If we have a system which can't exchange heat with the environment that is, by definition, an adiabatic process. Is it possible that in that situation the pressure lowers, the volume increases and the temperature stays the same?

I modified an incorrect derivation of entropy from phase space volume of a gas in the Wikipedia entry http://en.wikipedia.org/wiki/Adiabatic_invariant "Adiabatic expansion of an ideal gas" and I'd like to know if my modified derivation is also incorrect somehow. I realize it doesn't include...

Homework Statement Calculate the entropy for an irreversible adiabatic expansion of an ideal gas which goes from (Vi, Pi) = (9.01L, 3.00 bar) to (Vf, Pf) = (15.44L, 1.50 bar)Homework Equations \DeltaS = \int dq_{reversible}/T The Attempt at a Solution I understand that entropy is a state...

Using dU = dW, \frac{f}{2}NkdT = -PdV I eventually came to T^\frac{f}{2}V = \mbox{constant} I tried to then get it to the form in the book - PV^\frac{f+2}{f}=\mbox{constant} using the formula PV = NkT: \left(\frac{PV}{Nk}\right)^\frac{f}{2}V=\mbox{constant}...

In "Introduction to Thermal Physics" - Schroeder, the derivation for adiabatic compression: V^\gamma P = \mbox{constant} is derived by assuming the compression is still slow enough to be quasistatic. However, I'm still a bit confused with how slow is 'slow'. Quasistatic compression needs...

Is an adiabatic process isothermal also? Can anyone please tell me if it is necessary for an adiabatic process to be isothermal? Please explain with example.

Homework Statement Show that when an ideal gas expands adiabatically, the temperature and pressure are related by the differential equation: dT/dP = (2/f+2)(T/P). Homework Equations PV=NkT VT^(f/2) = constant V^(gamma)*P = constant The Attempt at a Solution I started off with the formula...

Homework Statement One mole of an ideal gas at 0 celcius is subjected to changes below, calculate the change in entropy of the gas: i) Gas is expanded reversibly and isothermally to twice its initial volume. DONE - 5.76 J/K ii)A similar expansion to i. is performed reversibly and...

Homework Statement Is it possible to have a process that is both adiabatic and isothermal. Homework Equations The Attempt at a Solution I think the answer is no. Because when a system is doing an adiabatic process, the total energy of this system must be changed. For an...

I'm having a lot of trouble with an adiabatic mixing process. This is what I know: There's an airstream coming from outside and its temperature is T1=5 'C, its relative humidity being \varphi1= 90% at a rate of 20 m3/min. Another airstream is coming from inside and its temperature is T2= 25...

Homework Statement An adiabatic process is performed on 15 moles of an ideal gas. The initial temperature is 320 K and the initial volume is 0.80 m3. The final volume is 0.40 m3. The adiabatic constant for the gas is 1.44. How much work is done by the gas? The answer is -32kJ Homework...

In polytropic process internal energy change is=mCv(T2-T1)? why is it not mCp(T2-T1)? Why are we not taking specific heat at constant pressure?

Why is there a difference when calculating pressure temperature and volume using the combined gas law, or when using adiabatic relations? As an idiot I am very confused. Why must I use a very similar equation to calculate the final temperature of an ideal gas but resulting in very different...

Hi there! I have to determine the work done of a reversible adiabatic expansion. Becauce the system is adiabatic: Q = 0 so \DeltaU = Wrev Becauce both the pressure and the volume changes I can't use W = pex\DeltaV. Homework Statement Cv, Cp, Ti, Tf, Pi, Pf, Vi, Vf are known The Attempt...

Hi everybody, this is my first post on your forum and i hope someone can help me :) the problem is i can figure out how to approuch this problem :s i do know that the process of the air descending is adiabatic but still i can't get it :( thanks for your help guys in advance. Homework...

Homework Statement Electrical current is passed through a resistor immersed in a liquid in an adiabatic container. The temperature of the liquid is varied by 1 degree Celcius. The system consists solely of the liquid. Does heat or work flow across the boundary between the system and...

An explosive liquid at temperature 300 K contains a spherical bubble of radius 5 mm, full of its vapour. When a mechanical shock to the liquid causes adiabatic compression of the bubble, what radius of the bubble is required for combustion of the vapour, given that the vapour ignites...

Disclaimer: English is not my native language. I'll try to do my best, but i could put some inappropriate term somewhere, if so please forgive me and feel free to correct me, the more i learn the best :P Hello guys. I'm new here, but i don't really think that this post could be addressed to...

Homework Statement At ground level in Colorado Springs, Colorado, the atmospheric pressure and temperature are 83.2 kPa and 25 C. Calculate the pressure on Pike’s Peak at an elevation of 2690 m above the city assuming an adiabatic atmosphere. Known Patm = 83200 Pa T0 = 25° C z-z0 = 2690 m...

Homework Statement A heat engine uses a diatomic gas that follows the pV cycle shown in Figure. Part 2→3 is adiabat, part 3→1 is isotherm, V=1040 cm3, P=100 kPa, T1=212 K. Determine the pressure at point 2. Determine the volume at point 2. Determine the temperature at point...

Hey. I'm supposed to calculate the work done in an adiabatic process, B-C, and I only know the values of the temperatures and the volume in the first point (point B). It is not known if it is a mono or diatomic gas, therefore i don't know the value of gamma. I've tried T*V^(gamma-1)=K and the...

how to create an adiabatic environment

Homework Statement http://img30.imageshack.us/img30/9954/72990922.jpg The Attempt at a Solution I would say the answer to (a) was no but that would be a guess. Does it have to do with the fact that it's done instantaneously, whereas to achieve anything like an irreversible process...

Just say an ideal gas goes through process such as isobaric, isochoric, quasistatic, adiabatic etc, is there any special cases where entropy is conserved, or am i thinking enthalpy. Also how is enthalpy found in adiabatic processes?

Homework Statement Ok, i have a cycle that goes from "a to b", via isobaric expansion, than from "b to c" vis isochoric decrease in pressure, and "c to a" via a adiabatic compression. Each occur under quasistatic conditions I just want to double check I've got the, changes in work, heat...

Homework Statement i have to find the W done in an Adiabatic, Quasistatic compression and I am not having much luck. Ive calculated it using (delta)U = Q + W, since Q = 0, hence W = change in internal energy However i want to calculate it using W = -(delta)P*V The Attempt at a Solution My...

Homework Statement The engine of a Ferrari F355 F1 sports car takes in air at 20.0 *C and 1.00 atm and compresses it adiabatically to 0.0900 times the original volume. The air may be treated as an ideal gas with \gamma = 1.40. Find Final Temp and Final Pressure Homework Equations...

If you accept that the 2nd law of thermo tells you that the Work_{net} = Q_{in} - Q_{out} it's easy to see why 2 adiabatic processes cannot cross on a PV diagram when connected by an isothermal process. however, why is the 2nd law true without taking a statistical approach? Why must...

trying to work through the exercise sheets that were given to us to prepare for exams when term starts up but I've come to a complete stop on this question and the following questions all seem to be based around it so i need your help! Homework Statement a certain gas occupies a bolume of...

what is it i cannot under stand this or other equation(Adiabatic Change p ⁢ V γ = const )

I'm deriving this formula for the adiabatic expansion of an ideal gas. PV^{\gamma} = Constant_2 there are 3 ways to expand to end up at same internal energy dU. 1. this is the direct adiabatic expansion from T1 to T3 dU_{systA} = -dW_{systA} = -P_{systA} dV where P_{systA} is a function...

Homework Statement A multicylinder engine in an airplane operating at 2500 rev/min takes in energy 7.89 x 10^3 J and exhausts 4.58 x 10^3 J for each revolution of the crankshaft. (a) How many litres of fuel does it consume in 1.00 h of operation if the heat of combustion is 4.02 x 10^7 J/L ...

I understand that adiabatic cooling is the reason as to why, a valve releasing compressed air from a tire, would become cold. But I'm having a hard time grasping why this actually happens. I've been searching online, and I can't seem to find the type of simplified answer I'm looking for...

Q1. ADIABATIC FREE EXPANSION(unrestricted and free) in vacuum gas a volume of gas is released expected expansion proceeds withouut change in internal energy therefore temperature is contant (joule's law) . there is no pressure acting on this system threfore no work is done...

Homework Statement In a diesel engine, atmospheric air is quickly compressed to about 1/20 of its original volume. Estimate the temperature of the air after compression , and explain why a Diesel engine does not require spark plugs. Homework Equations f/2*ln(T_f/T_i)=-ln(V_f/V_i) The...

Homework Statement The problem is derive the adiabatic processes for an ideal gas going through a point (v,p) on the p-V plane. Also, in terms of p,T and v,T. Draw the curves. Homework Equations First Law of Thermo Properties of an Ideal Gas Properties of Adiabatic Processes...

There are two compartments, each has half volume of the total volume, separated by an insulating partition. The whole setup is adiabatic. n mole of a monatomic gas with temperature T1 and pressure P in the left while in the right m mole of monatomic gas with termparture T2 and pressure P there...

I am reading quantum mechanics (Messiah) now. And I get confused about the condition for the validity of the sudden approximation in CH. XVII. The author use perturbation theory to derive the result T<<\hbar/\delta \overline{H} ,when the Hamiltonian change over time T. The condition tells...

is equation T2=T1*(p2/p2)^((k-1/k)) correct to calculate air temperatute during compression from 1bar to 2bar in a radial compressor? and equation for temperature drop throug intercoller T3=T2-ICefficiency*(T2-ambient_air_temp). Is this equation really so simple, what about air density when...

What would happen if adiabatic processes were applied in the context of a long-distance EPR Experiment? As background for my questions, see http://en.wikipedia.org/wiki/EPR_paradox" ) In the context of the foregoing, please visualize two particles that are...

Homework Statement An adiabatic process is performed on 15 moles of an ideal gas. the initial temperature is 320 K and the initial volume is 0.80m^3. the final volume is 0.40m^3. the adiabatic constant for the gas is 1.44 the heat absorbed by the gas in kJ is closest to a. 0 b.+54 c.-14...

Homework Statement twenty moles of a monatomic ideal gas (lambda=5/3) undergo an adiabatic process the initial pressure is 400kpa and the initial temperature is 450K. The final temperature of the gas is 320K. The heat absorbed by the gas in kJ is closest to? a.0 b.+54 c.+32 d.-54 e.-32...

http://session.masteringphysics.com/problemAsset/1013990/12/1013990E.jpg Which of the following statements are true about the first half of this process, just going from state A to state F? Both T and U increase. W provides energy input. Q provides energy input. Q is larger (in...

Hi, Can anyone tell me what this means? I'm trying to find the adiabatic expansion coefficient in order to use this air compressor calculator. http://www.engineeringtoolbox.com/horsepower-compressed-air-d_1363.html These are the variables I have at the moment... Number of stages-...

Homework Statement 14 grams of Nitrogen at 20 degrees Celsius in 1 atmosphere of pressure is compressed to a pressure of 20 atmospheres. What is its final temperature and what is the work done on the gas if the process is adiabatic? Obtain the compression ratio (i.e. Vmax/Vmin). How much...

Homework Statement A sample of 1.00 mol of an ideal gas at 300 K and 101325 Pa is expanded adiabatically in two ways: a) reversibly to .5 atm and b) against a constant external pressure of .5 atm. Determine the values of q, w, \DeltaU, \DeltaH, \DeltaS, \DeltaSsurr, and \DeltaStot for each...