Thermodynamics - 4-1 Moving Boundary Work equations

[@Wantootree210]

imma tell my children you're the one that makes me get to be an engineer. thank you sir !

[@ryanwaris7163]

Thank God I live in an era with KZbin 🙌🙌🙌🙌 Amazing work sir ❤️❤️

[@nicolascaleroarteaga4461]

You make it looks so smooth to get. Thanks a lot!

[@biniyamteketel5154]

in 16:40 we should multiply with the same term the whole expression either p1v1 or p2v2

[@helpcnarinceoglume]

Thank u so much Prof without u im definietly gonna fail thing course

[@SyedaExatyRohaizat]

Im struggling so much thinking where the ln suddenly came from in the isothermal compression of ideal gas eq, this really helps.

[@baranbilal5851]

you are god damn GOAT

[@sunmichoi6888]

Thank you so much!

[@fatihsevinc8626]

you are a legend sir

[@pear74]

this help me a lot thanks

[@EmmanuelGbiaye]

I love your videos sir

[@Yohannestad]

thank you sir ,are right professor

[@danirosero3]

does anyone know if when he says expansion = work out and compression = work in at 3:54, is it for reversible work?

[@haliltarbak2857]

i got a quesiton about spring work: in graph, you indicated that volume change will be equal indepent from the existence of spring. it doesnt make sense if T is constant which i dont think it is because PV is not constant in graph. So T is increasing am i right?

[@burhanurrehman2918]

I have a confusion when you explained Spring piston work: You wrote that Pressure increases linearly with V why is that so, because pressure decreases with increase in volume? which pressure are you talking about? Is that the pressure exerted by the gas or the pressure exerted by the spring piston?

[@engineeringdeciphered]

Because of equilibrium, the pressure exerted by the spring IS equal to the pressure exerted by the gas. One is pushing out, one is pushing in. And the force of the spring is F=kx so it is increasing linearly with x, so the pressure (since area is constant) is increasing linearly with x (and V).

[@burhanurrehman2918]

@@engineeringdeciphered thanks sir :)

[@اياتعلي-ح6ح]

عاشت ايدك ❤️😞

[@AboAbdulrahman_YT]

انتي الي فبالي؟🙄

[@KAChiewWeiNee]

Thank a lot !!!!

[@EmmanuelGbiaye]

Sir will you explain how you got the last question?😢

[@minikubik24]

in 9:15 shouldn't be there a minus?

[@buluud]

subtraction in logarithms are just division. lnV2-lnV1=ln(V2/V1)

[@baranbilal5851]

ty

[@judg3potat030]

17:53 İS THAT A STAR WARS REFERENCE O7

[@judg3potat030]

GÜLHANE PARKI

[@XplosiveAction]

For a constant volume process would it not matter if temperature changes? such as a rigid body container problem, in which you have 2 states at different tempts, changing pressures, and therefore constant volume? Its still 0?

[@engineeringdeciphered]

XplosiveAction correct. For a constant volume process the boundary work would be zero, even though temperature and pressure are probably changing. If the volume (and therefore the “boundary”) is not changing then the boundary work is zero.

[@XplosiveAction]

Engineering Deciphered thanks for the very quick reply I appreciate it greatly. I was asking because specifically I’m working on a problem right now which only states: “A rigid body contains superheated water vapor at 2.5MPa and 800 deg.Celsius. The system is cooled until the water is at 500kPa and 500 deg.Celsius. Calculate the boundary work done in kJ.” And the only thing that I learned was that the Energy Balance and Rate Balance equations made use of internal energy rather than enthalpy in those equations for a rigid body, but nothing about how to go about a rigid body problem since that was the only exception for the topic I’m learning.

[@engineeringdeciphered]

XplosiveAction you’re right about internal energy and enthalpy. Generally when I say “rigid tank” in a problem I want that to mean constant volume. That’s what I’d assume “rigid body” means, but other teachers might describe it differently.

[@matthewerskine918]

Im always confused is it PV = RT or PV = mRT or PV = nRT

[@engineeringdeciphered]

It’s both Pv=RT or PV=mRT because v=V/m. Lowercase v is specific volume, uppercase V is volume. The units will help you out- units have to be the same on both sides of the equation. I never use nRT.

[@matthewerskine918]

@Engineering Deciphered Thank you so much. Ya I went back and understand it now. Again thank you so much for the quick reply. You are a legend.

[@EmmanuelGbiaye]

​​@@engineeringdeciphered n=mass/molarmass which makes sense and is consistent with what you've been teaching. R=will be the universal gas constant(not for a specific substance).

[@omarhsh8069]

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