Hello Andrea, great question. So if we go to page 109 on reference manual, at the bottom of the page, there is a definition of the energy line, which states that the total head line is the sum of pressure, velocity and elevation heads. I hope this helps and good luck with your exam!
That is a good question. So the question asks to find the energy of this pipe. Note that the pipe is in a horizontal line, so the total energy is constant. Therefore, we have energy grade line. Now, energy grade line is the sum of pressure, velocity and elevation. You can also check the definition of the energy grade line in the reference manual page 109. I hope this makes sense and good luck with your studying!
If the fluid in the pipe is not specified, we usually assume it's water. However, in your FE exam, you will be given all the information you need to solve the problem.
Thank you for your help I’ve been out of school for 5 years and I forgot a lot about fluid mechanics and a lot of subjects lol. I did have a question though I kept the units in pascals(200) and put it over 9,810 N/m^3 Is that part of the answer the same?
You are welcome and thank you for watching my videos. You can totally do that and you will get the same answer because pressure head has a unit of length, so in this example, it is going to be in meters (SI units), so when you have Pa (N/m^2)/ (N/m^3), after cancelling the units, you will get meters, so having N or KN, it doesn't affect the rest of the equation.
Hello John, one way to find the equations on the reference is by clicking control+F or you can also use control+shift+F, which is similar to what you would have access to during the FE exam. I would also recommend that when you are studying or doing practice problems and practice exams, you should always have your reference handbook open so that you remember where the equations are and you would also know which equations are provided to you. However, please keep in mind that some subjects, it is hard to try to look for the equation if you are not sure what equation you need. For example, when you are trying to solve for head loss in fluids, not only you need to know that you need to use Darcy (assuming it is turbulent flow), but also you need to know that you have to calculate Reynolds number and epsilon/D, then use the moody chart to find the friction factor and finally use Darcy to calculate for the head friction. In the reference handbook, it gives you all those equations but they are scattered, so you need to know it. However, in some other subjects, like environmental, you can easily look up the equations and start solving right away. I hope this makes sense and good luck.
That sounds like a Darcy weisbach equation and lately I have been looking in the reference manual when I haven’t been able to solve or figure out the lectures I have been solving and is epsilon pi and yeah those take more skill and environmental does seem like more plug and chug but a good amount of chemistry to remember too did you have a lot of chemistry in your exam?
I have been studying my ass off and when I got one of your concepts I got them so I hope you have more examples to display they are incredibly helpful and I wish there was a way to do control f before the exam so you can simulate it when you practice problems
Or if you have a downloadable pdf of the reference manual which I just recently did I didn’t know you would be able to do shift control f in the equation
I actually had no chemistry related questions. Also a lot of my clients did not get a lot of chemistry questions, so I would not focus too much on it, maybe just review it a little bit and focus more on the activated sludge and sludge processing, wastewater collection and treatment, and water and air quality.
It doesn't really. It is more of a convention, than any physical reality, that we express it in units of meters. We divide all terms by g, so we can relate to the other forms of energy as an equivalent height called "head". Gravitational potential energy per unit mass, is z*g, and we divide through by g to turn J/kg into meters. Pressure energy has nothing to do with gravity, and neither does kinetic energy, nor frictional losses, nor shaft work. I prefer to see in the following form, since only the energy associated with the z-terms have anything to do with gravity: P1/rho + v1^2/2 + g*z1 = P2/rho + v2^2/2 + g*z2 In this form, all terms directly tell you the energy per unit mass.
Hi, I am from VA dulles, I took the FE exam more than 3 times and did not pass! I do not know what I shall doing at this time coz my FE cert. Could Act negativley on my current position.! Thanks
Hello Ayman, I am sorry to hear about your test. Why don't you send me all the diagnostics to my email (engenieer.online@gmail.com) and I think I might be able to help you!
Hi, I see the Energy Eq in the handbook however is not H= z+ v^2.. etc the H is in the same side as z + v^2 etc.. how did you get that initial eq?
Hello Andrea, great question. So if we go to page 109 on reference manual, at the bottom of the page, there is a definition of the energy line, which states that the total head line is the sum of pressure, velocity and elevation heads. I hope this helps and good luck with your exam!
Allo Kenza, j’aime beaucoup tes vids, STP continue ton bon travail 🥰
Merci beaucoup Karl. We are so happy to help!
Awesome! Please keep these videos coming, really need help on fluid mech especially. Thank you!
Hello Patricia, I actually have so many videos on fluid mechanics, statics, Eng. Economics on my Patreon page in case you are interested 😊
Very helpful, I stated studying for my FE civil. Thank you for the good videos 😁😁
Can you explain how you came up with that version of the energy equation (e.g., how you canceled out the other pressure and velocity terms)
That is a good question. So the question asks to find the energy of this pipe. Note that the pipe is in a horizontal line, so the total energy is constant. Therefore, we have energy grade line. Now, energy grade line is the sum of pressure, velocity and elevation. You can also check the definition of the energy grade line in the reference manual page 109. I hope this makes sense and good luck with your studying!
How do you know that the specific weight is for water?
If the fluid in the pipe is not specified, we usually assume it's water. However, in your FE exam, you will be given all the information you need to solve the problem.
@@Genieprep Thanks
Thank you
Thank you for your help I’ve been out of school for 5 years and I forgot a lot about fluid mechanics and a lot of subjects lol. I did have a question though I kept the units in pascals(200) and put it over 9,810 N/m^3 Is that part of the answer the same?
You are welcome and thank you for watching my videos. You can totally do that and you will get the same answer because pressure head has a unit of length, so in this example, it is going to be in meters (SI units), so when you have Pa (N/m^2)/ (N/m^3), after cancelling the units, you will get meters, so having N or KN, it doesn't affect the rest of the equation.
Also if you have any tips on how to find the concepts faster on the reference manual that would be awesome thank you again!
Hello John, one way to find the equations on the reference is by clicking control+F or you can also use control+shift+F, which is similar to what you would have access to during the FE exam. I would also recommend that when you are studying or doing practice problems and practice exams, you should always have your reference handbook open so that you remember where the equations are and you would also know which equations are provided to you. However, please keep in mind that some subjects, it is hard to try to look for the equation if you are not sure what equation you need. For example, when you are trying to solve for head loss in fluids, not only you need to know that you need to use Darcy (assuming it is turbulent flow), but also you need to know that you have to calculate Reynolds number and epsilon/D, then use the moody chart to find the friction factor and finally use Darcy to calculate for the head friction. In the reference handbook, it gives you all those equations but they are scattered, so you need to know it. However, in some other subjects, like environmental, you can easily look up the equations and start solving right away. I hope this makes sense and good luck.
That sounds like a Darcy weisbach equation and lately I have been looking in the reference manual when I haven’t been able to solve or figure out the lectures I have been solving and is epsilon pi and yeah those take more skill and environmental does seem like more plug and chug but a good amount of chemistry to remember too did you have a lot of chemistry in your exam?
I have been studying my ass off and when I got one of your concepts I got them so I hope you have more examples to display they are incredibly helpful and I wish there was a way to do control f before the exam so you can simulate it when you practice problems
Or if you have a downloadable pdf of the reference manual which I just recently did I didn’t know you would be able to do shift control f in the equation
I actually had no chemistry related questions. Also a lot of my clients did not get a lot of chemistry questions, so I would not focus too much on it, maybe just review it a little bit and focus more on the activated sludge and sludge processing, wastewater collection and treatment, and water and air quality.
Can you explain why the unit of energy is in meters? Thanks.
It doesn't really. It is more of a convention, than any physical reality, that we express it in units of meters. We divide all terms by g, so we can relate to the other forms of energy as an equivalent height called "head". Gravitational potential energy per unit mass, is z*g, and we divide through by g to turn J/kg into meters.
Pressure energy has nothing to do with gravity, and neither does kinetic energy, nor frictional losses, nor shaft work.
I prefer to see in the following form, since only the energy associated with the z-terms have anything to do with gravity:
P1/rho + v1^2/2 + g*z1 = P2/rho + v2^2/2 + g*z2
In this form, all terms directly tell you the energy per unit mass.
Hi, I am from VA dulles, I took the FE exam more than 3 times and did not pass! I do not know what I shall doing at this time coz my FE cert. Could Act negativley on my current position.! Thanks
Hello Ayman, I am sorry to hear about your test. Why don't you send me all the diagnostics to my email (engenieer.online@gmail.com) and I think I might be able to help you!
@@Genieprep Sure I will do next week thanks alot for your kindness and help.