"Law of Thermodynamics" from engineer pocket guide 2

[Tunalover]

Folks,
I have "The IDC Pocket Guide for Engineers" which seems to contain a lot of useful information. But looking it over I found an error in a temperature conversion formula [T_f=(5/9)(T_c+32)] and a "Law of Thermodynamics" as they call it:

C_p/C_v=5/3

Has anyone else seen this "Law" before?



ElectroMechanical Product Development
(Electronics Packaging)
UMD 1984
UCF 1993

https://www.youtube.com/watch?v=BKorP55Aqvg

 

[georgeverghese]

Fake thermodynamics?

 

[willard3]

The first thing here is to tell us how C sub p and C sub v are defined.

 

[Tunalover]

C_p=specific heat at constant pressure
C_v=specific heat at constant volume


ElectroMechanical Product Development
(Electronics Packaging)
UMD 1984
UCF 1993

https://www.youtube.com/watch?v=BKorP55Aqvg

 

[Latexman]

That's for a monoatomic gas like Helium. A diatomic gas, like air (O2 and N2) is 7/5 ~ 1.4. See here.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[Tunalover]

Thanks for that Latexman!

ElectroMechanical Product Development
(Electronics Packaging)
UMD 1984
UCF 1993

https://www.youtube.com/watch?v=BKorP55Aqvg

 

[MortenA]

so note that its for an ideal gas - for many gasses at near atm pressure and ambient temp this will be true.
Best regards, Morten

 

[Harvey Peters]

probably the mistake is a misprint where the second closing parenthesis is after 32 in lieu of after Tc

 

[IRstuff]

The equation is Tf = (9/5*Tc)+32, so not just a parenthesis error.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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