Thursday 7 September 2017

thermodynamics - Error in Sear's and Zemansky's University Physics with Modern Physics 13th Edition (Young and Freeman)?


I was reading up on the Ideal Gas Equation in University Physics with Modern Physics by Young and Freeman when I chanced upon a seemingly illogical mathematical equation.


Can anyone rectify this error? Or is it misunderstanding on my part?



Here is the portion (Page 600, Chapter 18, Equation 18.12):



$$pV = \frac{1}{2}Nm(v^2)_{av} = \frac{1}{3}N\biggl[\frac{1}{2}m(v^2)_{av}\biggr]$$



It should be clear that $\frac{1}{3} \neq (\frac{1}{3} \times \frac{1}{2})$.



Answer



Nice catch!


For reference here is the book page.


:enter image description here


See , though it may error in printing or anything else.The final equation they get $$pV=\dfrac23K_{tr}$$ is very correct.



The correct form of $eq.(18.12)$ must be $$pV=\dfrac13Nm(v^2)_{av}=\dfrac {\color{red}{\huge{2}}}3N\bigg[\dfrac12 m (v^2)_{av}\bigg]$$


No comments:

Post a Comment

Understanding Stagnation point in pitot fluid

What is stagnation point in fluid mechanics. At the open end of the pitot tube the velocity of the fluid becomes zero.But that should result...