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For Impulse Momentum priniciple,it is the change in force or the net force in the system is equal to change in momentum right. why did you use F as the resultant force. The resultant force should be zero right since it is acting equal and opposite direction.
Correction: For any softening problem we will use the EQUIVALENT RATIOS. Using this ensures the amount of lime (or soda ash) added will exactly match the amount required to neutralize or precipitate the hardness ions, based on their charge equivalency. The Stoichiometric Ratio isn't accurate enough since it's based only on the balanced chemical equation which tells us the ratio of moles of reactants required to completely react with each other. A better method is to use the equivalent ratio which accounts for both the charge and the amount of substance. It is used because water softening processes typically involve ionic reactions where the focus is on balancing the positive and negative charges rather than just the moles of reactants. The corrected proportion equation should be: 2 equivalent of Lime/1 mol Mg(HCO3)2 = X / 50 mg/L The equivalent ratio for the reaction is equal to the molar ratio. This won't always be the case but it is so for these chemical softening equations.
Why is the value of K not taken to 1 in Manning's equation, whereas it is taken as 0.849 (SI units) in the Hazen-Williams equation? Shouldn't K in Manning's equation also be expressed in SI units?
Your question on it being a face or spade card, your question did not differentiate it being a face spade card, so why is it not a face card of the other suits?
If the tolerance of the data in the multiple choice be a lot, it is a good idea, but in this case if you use data for the temp. of 45, the enthalpy is given 2391.66 Kj/Kg which is close to answer number two than answer number three.
My strategy has always been to link topics as much as possible. Say I learned about semiconductor physics today and BJT-MOSFET circuitry tomorrow. I must remind myself what is happening at the bandgap/electron level while this circuit is functioning. Then the next day I do Karnaugh maps and remind myself how the logic gates in a flip flop function at the MOSFET level. The next day I write in C++ and I remind myself how Assembly coding functions by managing flip flops which are just semiconductors and bandgaps. Everything is connected to everything. Don't suffer from tunnel vision.
WATCH OUT! @25:17 the FBD of box A should include the friction force between block A and block B. The corrected FBD is shown below: www.directhub.net/wp-content/uploads/2024/08/image-26.png
Hi Farouq, @25:49 shouldn't there be a friction acting between A&B acting on Block A? I just wanted to be sure. Thank you for the videos! I am feeling confident in the exam on 08/26!
Hello! Oh wow. I can't believe I missed that haha. Luckily, it won't impact the final analysis if we are asked to find the Force (F). But if we were asked to find tension (T) then it would be important. Here is the corrected FBDs: www.directhub.net/wp-content/uploads/2024/08/image-26.png Thank you for letting me know. You got this!
Hi Faruq, I hope this message finds you well. I am an international student currently preparing for the FE exam. I have been using the "FE Review Manual" by Michael R. Lindeburg (Third Edition) for my studies, but I’ve found that it doesn’t cover all the topics or provide enough practice problems. As an international student, I find the cost of enrolling in your course to be too high for my budget. Could you please recommend a comprehensive study book that covers all the necessary topics, along with a good practice problem book to help build my confidence? Thank you.
For others, the reason you can add the "n" variable for moles into the equation is you can derive that from the gas constant equation and the molecular weight equation in the FE handbook. It's written as Rbar (bar on top of R symbol) in the handbook. That confused me at first, so hope it helps others!
Hi! Great video, thank you! Can you explain a bit more as to why the amount of lime needed is the same amount as the CH? Is it related to the stoichiometric ratios in the lime softening equations?
Hi, could you please explain when to use the two different definitions for TH? You said its Ca2+ + Mg2+, but you also said its the sum of CH + NCH. I'm confused as to when I would use each definition. Thanks in advance!
Hello! Both defintions are correct. Total hardness is the summation of the MAJOR "multi-valent" cations which tend to be Calcium (Ca2+) and Magnesium (Mg2+). There are other cations that contribute to the total hardness, but these are negligible when compared to the high concentrations we get from Ca2+ and Mg2+. Total hardness is also defined as the Carbonate Hardness (CH) and Non-carbonate Hardness (NCH). The carbonate hardness consists of the hardness has the bicarbonate ion attached to either Ca2+ and Mg2+. This is easier to remove. The non-carbonate hardness DOES not have the bicarbonate ion (HCO3-) attached to the Ca2+ and Mg2+. This is much harder to remove and requires the addition of soda ash. Check out the summary notes taken directly from the DirectHUB course: drive.google.com/file/d/1T6FLrGjyA-0bdA8EXdd8TuMkcXiZw1IT/view?usp=drive_link
Thank you! The equivalent weight formula is not in the FE Handbook. The only relevant table provided is on page. 344 in the FE Handbook. Definitely know this table!
Thank you so much for working through a handful of fluid mechanics problems! Incredibly helpful resource for studying for the FE environmental exam. Cheers!
Since Patm acts on both sides (almost alwya sthe case), then we will drop it and only work with gauge pressure. Please refer to the image below: ibb.co/5xCy3k3
@@directhubfeexam I'm also confused about this. How do you know to use Ix instead of Ixc? Ixc in the handbook is what this person says: bh3/36. Ix is what you used: bh3/12.
Hello Majeed! Just trying to go a little fast on this one. I did, but did not write down the steps since we already did it for alternative 1. The video should have stated that.
Hi! Thank you so much for the videos, it’s been a great review before I take the exam in September. I just wanted to add; another shortcut would be to just divide the calculated cooling rate by the calculated compressor power to find the COP, so you don’t have to use the last equation.
Hey! I'm glad you're finding the videos helpful! Interesting...Did not know that! Thank you for sharing this. Thermodynamics is one of those courses I wish I took in school haha. Really enjoyed making these videos. Keep doing your thing Aiden!
Hello, in the cross-section sketch you drew, the 220' and the 205' should be 195' and 175' respectively. The well head should be above the water table. so we subtract 220'- 25' =195' and 205'-30' = 175'. Can you please verify? Thank you.
Thank you for this video! You got a new subscriber. I am taking my first FE exam in a few weeks. I am getting anxious due to not having as much study time as I feel I should have done (just graduated). Any tips outside of these for me?
Hey! Good to have you in the Directhub clan! Don’t worry. Since you recently graduated I feel like you’ll tackle most problems with confidence. The FE exam is designed to test fundamental problems that can be solved within 1-4 minutes max. If you can grab enough correct answers from the basics, you’ll surely pass. There will be crazy curveball conceptual questions. Those are tough. Try to eliminate answer choices for these then make an educated guess based on your gut engineering judgment. In general, please do your best to not get hung up on specific problems. Attempt each problem but if you’re not getting anywhere, flag it for review and come back to it. Also, sometimes you can manage to arrive at the right approach or equation using the FE Handbook. Make use of the FE Handbook as much as you can! Even for conceptual questions. Finish off your prep by doing plenty of hands on practice. This can be quizzes and even better timed full length exams! You’ll do great. Make sure to get lots of rest and don’t study a day before the exam. You got this!
