4.36 Nitrogen, modeled as an ideal gas, flows at a rate of 3 kg/s through a well-insulated

4.36 Nitrogen, modeled as an ideal gas, flows at a rate of 3 kg/s through a well-insulated horizontal nozzle operating at steady state. The nitrogen enters the nozzle with a velocity of 20 m/s at 340 K, 400 kPa and exits the nozzle at 100 kPa. To achieve an exit velocity of 478.8 m/s, determine (a) the exit temperature, in K. (b) the exit area, in m2.
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Textbooks:
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Fundamentals of Engineering Thermodynamics 8th Edition (Wiley):
Moran, M. J., et. al., 2014, Fundamentals of Engineering Thermodynamics, 8th ed., Wiley, Hoboken, NJ.
Purchase a textbook here: www.amazon.com...
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Engineering Mechanics Statics (Pearson):
Hibbeler, R. C. Engineering Mechanics Statics. Pearson Prentice Hall, Pearson Education, 2016.
Purchase a textbook here: www.amazon.com...
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For problem solving requests, visit www.georgeramm...
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I'm looking to strengthen rising engineering students' understandings Mechanical Engineering. I believe that the more knowledgeable our field is, the more real world problems we can solve. If you learned anything from watching this educational video, I'd appreciate your support through liking and subscribing to optimize my channel for students using search engines.

[@gr_engineering]

Note: At 3:24, I said “horizontal” implies no change in kinetic energy, I meant to say potential energy, NOT kinetic energy. Sorry for any confusion.

[@donquixotedbob842]

i've submit my problem requests sir(chapter 3 number 22). please check out

[@gr_engineering]

@@donquixotedbob842 Hello, thanks for the request! I had issues emailing you back to the email address you submitted on the problem request form. The explanation can be found here: kzbin.info/www/bejne/oIPHeJh4q6-Kjqc

[@GooseHonkHonkHonk]

It looks like your first ideal gas equation - p(V-dot)=mRT should be p(V-dot)=(m-dot)RT. Thank you for these videos! These are a lifeline for me when I get stuck.

[@gr_engineering]

Thank you for the catch, yes you are correct, V̇ must be accompanied by ṁ. I’m glad you find these videos helpful!

[@anawaz189]

4:34 why are you able to use the value for specific heat at constant pressure for nitrogen, the pressure is changing, no?

[@gr_engineering]

That is an excellent question. Because we are applying the first law of thermodynamics over an open system, we deal with specific enthalpy, as opposed to specific internal energy. The cp constant is a function of the specific enthalpy, while the cv constant is a function of the specific internal energy. Therefore, we had to use the cp constant in this case. The names of these variables can be very confusing, but I hope this explanation helps!