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I wonder why B1(t) = B11(t) = 0 you say that it doesn't exist yet but how can this be possible isn't region 1 and 11 have fluid so where there is a fluid there must be a property for it this is how i think if there is something wrong i want to know what is right?
Initially the system and control volume coincide at time t. Regions I and II have zero volume at this time, so they do not have mass (or any other extensive property) yet.
If you look at the image at time t, there is no B1. B1 is the region in which new fluid flows into the CV. So some time needs to pass (for example, time dt) in order for new fluid to enter the CV.
Sir, At 10:38 while deriving the value of B' in should there be a negative sign since after taking after the dot product the whole value would be negative anyways, and initially when we said B'(out)-B'(in) are we not just considering their magnitudes only. and its exactly same as B'(out)+B'(in) when considered them as vectors. the result does not change anyways
Clean explanation leads to a better understanding and that happened with me. Thanks for sharing the information. But I have a doubt and that is why are you considering dB=b*rho*dA*dLn whereas the dV considered is in the direction of V vector?
What an awesome video! Quick question. You said that the inflow region of the CS is AFC and the outflow region is ADC, but AFC and ADC are 2d curves and not 3d surfaces. Shouldn't the inflow and outflow regions be 3D surfaces, since they contain a volume (and not an area)?
These videos are spectacular. They are helping me refresh and prepare for courses in my graduate program. Is it possible to get ahold of the slideshow material? I can't find any lecture slides of this calibur on this topic.
At the moment, the slides are provided to students enrolled in certain sections of ME 311 at Cal Poly Pomona. We do not know whether the slides will be available to the general public in the future though. However, the videos will remain on RU-vid for the foreseeable future.
Plzzz help me: I am trying to remember a theorem that study the movement of water particles. This theorem compasses two parts one is real and the another is imaginary part. If you know plz reply by the name of theorem or if you have a video share here as a link because I am tired from searching a video about this
BTW, mass ``m'' is not a property neither ``extensive'' nor ``intensive'' since it is the connection: B=mb, where ``B'' is extensive and ``b'' is intensive properties. For example, pressure and temperature are not neither intensive nor extensive, although they are properties of any (thermodynamical) system. On the contrary, the specific volume v=V/m is an intensive property of the system (open or closed!).
The momentum of a system is conserved only when there is no net external force on it. The same is true for energy w.r.t a given system. So then dont you think the laws should not really be named as 'conservation' laws ? I mean I do understand the idea behind these laws, but the term conservation sounds a bit misleading, isn't it ? For eg: If the property under consideration is the mass of the system, we know that it doesnt change over time, coz the amount of matter in the system is fixed, as the system has been 'identified'. So the term on the LHS of the RTT drops to zero and we then rightfully say that the mass is 'conserved'. But the same is not always true for momentum or enery of a system, as they often change, given a net external force or an energy transfer. What do you think ?
The CV is fixed, so Bcv(t+dt) is the amount of B (mass, momentum, or energy) within the red dashed line at time t+dt. This can be different that the amount of B in the CV at time t. For example, let's say B is mass and imagine a denser fluid enters the CV in region I during time dt. In this case, Bcv(t+dt) > Bcv(t).
I don't concur with my peers, I think this is a lousy explanation: It would be much better if you started out by giving an intuition of what the theorem attempts to solve, a general picture if you will. Then, if your objective is to impart a working, operational understanding of the subject, you can progress in the way you did. I would, though, prefer if, at every point, you stopped and explained where you're heading and why.
