Typo on Supplied Reference Handbook?

[Karl T]

Hey, I'm taking the FE on Saturday, doing some problems online and one involved pressure volume work of a polytropic process. Page 74 midpage or the equation is

wrev = n(P2v2 - P1v1)/(1-n)

where constant = Pv^n, wrev is per mass work, v is specific volume.

is the 'n' in the numerator supposed to be there, did the calculus on deriving it and I couldn't get the math to work, and looked it up online and the 'n' was also absent.

thanks guys

http://en.wikibooks.org/wiki/Engineering_T...amics/First_Law

 

[adamgram]

Hey, I'm taking the FE on Saturday, doing some problems online and one involved pressure volume work of a polytropic process. Page 74 midpage or the equation is
wrev = n(P2v2 - P1v1)/(1-n)

where constant = Pv^n, wrev is per mass work, v is specific volume.

is the 'n' in the numerator supposed to be there, did the calculus on deriving it and I couldn't get the math to work, and looked it up online and the 'n' was also absent.

thanks guys

http://en.wikibooks.org/wiki/Engineering_T...amics/First_Law

I'm taking it on Saturday too. I spent all day studying, came home and had 2 drinks. If not for those 2 drinks I might be able to figure it out but I did look at the previous version of the FE reference manual and it says the same thing, for whatever that is worth. I'll take another look tomorrow. It's also the same for the isentropic case which is basically the same thing so I'm guessing there is something to it.

 

[Karl T]

Never mind, the equation is for isentropic expansion/compression of an OPEN system. The equation in question reduces to

w = h*delta T, which is what you'd expect from an open system disregarding kinetic or potential energy.