If your system is composed of the two rivers and the pump, then there will be no potential energy change for that system. I guess your system as per your calculation is from pipe inlet to pipe outlet including the pump ? The potential energy will be based on system inlet to system outlet, which is 40 ft.
When you were calculating the potential energy on the yowling cat problem, I think you were meaning to multiply 8.346 to the gravity and height, right?
+yasmine bouguezine Delta U is the internal energy change. If there is no kinetic or potential energy change (for the closed system) then, yes, Delta U = Q (heat) - W (work).
+APMonitor.com So i deduce here that... the gains or losses of heat or/and work are not due only to its internal energy like it has always been the case for our teacher ? ,(THANK YOU SIR )
An energy balance on a human? Yes, I think scientists may do this when studying weight loss, diet, and exercise. I couldn't point you to a particular reference, however, but a quick search in the scientific literature may turn up some results.
These videos are part of a Chemical Engineering course on material and energy balances. Here is the complete playlist: ruclips.net/video/QUkCestIxFI/видео.html I also recommend the LearnChemE channel. You may need some additional background information to understand this material.
If your system is composed of the two rivers and the pump, then there will be no potential energy change for that system. I guess your system as per your calculation is from pipe inlet to pipe outlet including the pump ? The potential energy will be based on system inlet to system outlet, which is 40 ft.
When you were calculating the potential energy on the yowling cat problem, I think you were meaning to multiply 8.346 to the gravity and height, right?
Yes! At 21:49, I used 8.314 instead of 8.346 like I had on the line above. I must have been thinking about the universal gas constant (8.314 J/mol-K).
Hey , how do I know if there is any work done to or by the system?
A pump is an example of work done on the system. A generator is an example of work done by the system.
very helpful, thank you!!
thanke you so much , really helped me
Thanks a lot..really useful.
And the term q u were saying is actually head provided or released?
Q is heat added to the system.
Is delta U in our equation equal to Q-W ?? helP !
+yasmine bouguezine Delta U is the internal energy change. If there is no kinetic or potential energy change (for the closed system) then, yes, Delta U = Q (heat) - W (work).
+APMonitor.com So i deduce here that... the gains or losses of heat or/and work are not due only to its internal energy like it has always been the case for our teacher ? ,(THANK YOU SIR )
Yes, the closed system energy balance should include kinetic and potential energy terms as well. However, in many cases these are negligible.
+APMonitor.com NOW i GOT it , Thank thee SO much ! thou are awesome :)
how did you solve the mass work per mass in ex 2 i cant figure out? My answers are the not same as yours? plss help me. thank you !
My solution is shown at 7:15. Did I make a mistake on the unit conversion?
APMonitor.com when I calculated it my answer is 0.05 . how did you get the 0.33? ☺
Thanks for catching that - it may have been a calculator error. The correct answer is 0.05 BTU/lbm or 1.5e-5 kW-hr/lbm.
APMonitor.com thank you very much! These really help us!
That delta u is internal energy isnt it?
Delta U is the internal energy.
Yep
damn those imperial units are very confusing what on earth is Btu??
BTU = British Thermal Unit. Life is much easier in SI units.
Thank you. Have you ever heard of this being done on a human?
An energy balance on a human? Yes, I think scientists may do this when studying weight loss, diet, and exercise. I couldn't point you to a particular reference, however, but a quick search in the scientific literature may turn up some results.
Sir i have no clue what my sir teach me. Or what u are teaching.
These videos are part of a Chemical Engineering course on material and energy balances. Here is the complete playlist: ruclips.net/video/QUkCestIxFI/видео.html I also recommend the LearnChemE channel. You may need some additional background information to understand this material.