Fundamentals of Fluid Mechanics Questions and Answers  




If there is enough information to take this into account, then yes you have to. If not you have to mention this in the assumptions.




No, you shouldn't make this assumption. Your answer should work for any type of duct as long as the intake is aligned with the $y$ axis.




Yes this is correct. However, if you do assume that the water temperature is constant in time, you need to justify this assumption. Why would this be the case? Explain. Further, only one question per post in the future.




At constant volume, there is a relationship between $dm_{\rm a}$ and $dm_{\rm l}$ (if a bit of air mass is added to the volume, you can find exactly what the bit of water mass must be removed). Use this relationship to get rid of $dm_{\rm l}$.




The crosssectional area of the reflected snow can (in fact, must!) be found through Bernoulli. It's indicated in the question statement that there is no friction, so Bernoulli's equation certainly applies. Also note that measuring crosssectional area of the reflected snow can't be done with certainty given the drawing dimensions (in the figure, it wasn't clear what $d$ of the reflected snow stood for exactly). Also, $B/\cos(30)$ is not the width of the reflected snow — build a 3D model of the snow with a sheet of paper to convince yourself of this. Albeit coming a bit later than I would like, thank you for the question: I can see how the dimension $d$ of the reflected snow was not clear in this respect and made a change in the figure in consequence.



$\pi$ 