Educational videos about the Bible, Fluid Mechanics, Excel, Science, Air Pollution, Indoor Air Quality, Math, Statistics, and more. Produced by Dr. John M. Cimbala, Professor of Mechanical Engineering, Penn State University, University Park, PA.
The short (2 to 3 minute) videos are fast-paced and humorous with several characters who interact with each other. If you like to learn quickly, this channel is for you. There is a playlist for each category enabling you to watch all videos in a category with one click. Here are three of the most popular ones:
Probably. I have been asking someone to send me evidence that some old Bibles really did say lion and lamb, but so far nobody has found one. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your very kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you. And Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
You are welcome! I am glad you find them useful. Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Yes, he is! Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
whats the difference in back pressure and exit pressure? Back pressure what causes the fluid to flow due to the pressure gradient but I don't get how thats different from pressure at the exit. is pressure at the exit not also the same thing?
Yes if the flow is subsonic, but if the flow is choked, the Mach number is 1 right at the throat. In that case the two pressures can differ. Think about a perfect vacuum, for example. Pback = 0, but Pexit is some pressure much greater than zero. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
“What thing soever I command you, observe to do it: thou shalt not add thereto, nor diminish from it. Deuteronomy 4:2 KJv 2 Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the Lord your God which I command you. * * Revelation 22:18-19 KJv 18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: 19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.” (Deut. 12:32.)
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
@@johncimbala Yes Prof, I actually do use your videos on Fluid mechanics and your textbooks on thermodynamics and fluid mechanics to teach year 2 students at Nile University of Nigeria. It is an honor getting to talk here and I would love to connect more. Thank you Prof.
Thanks Professor for your beautiful explanation. Just a slight point: I think the mod(C1) should be from the bottom of surface to the isobar since r=0 should give the height.(around min 4:30)
For a particular isobar, the height |C1| is the same at any r. That was the point - the isobars are just the surface shape moved down by some distance as pressure increases. Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Can you give a reliable reference for this claim? Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
@@johncimbala of course not , the whole thing is a fairytale. But the tumeric was known as gold in those times. And it's anti inflammatory so it would make more sense.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
I have been utterly baffled and terrified that I am about to fail my hydraulics test. I feel ready to take on some practice problems now! there's hope! Thank you Dr. Cimbala!!!!
Glad to be of help! Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
For more explanation: Cavitation refers to the formation of vapor bubbles in a liquid when it's subjected to rapid pressure changes. In the case of breaking the bottom of a bottle with a strike to the top, the force from the impact causes a sudden pressure drop in the liquid inside the bottle, particularly when it's partially filled with water. Here's how cavitation leads to breaking the glass: -Rapid pressure drop: When the bottle is hit, the force travels through the water, causing a sharp drop in pressure. This drop in pressure causes vapor bubbles (cavitation bubbles) to form near the bottom of the bottle. -Collapse of bubbles: These vapor bubbles are unstable and collapse almost instantly as the pressure normalizes. When the bubbles collapse, they generate intense localized forces. -Glass shattering: The collapse of these bubbles creates shock waves and microjets of water, which apply enough localized stress on the bottom of the bottle to cause it to break. Thanks Dr. for this video.
Yes, much more detail than could be covered in two minutes! Thank you for your detailed comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 460 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Not sure what you mean, but thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 460 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 460 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Ha! Then it is good that you watched my video! Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 460 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are more than 460 free videos about the Bible, fluid mechanics, science, math, statistics, air pollution, and other topics. I would greatly appreciate it.
The fluid still cannot gain mass right the area between the atoms is changing, Right? That means that for water heating it up will expand and when gass heating it up it will decrease.
Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Hi professor John ,I have a question here about at 0:24 . Is _stream line_ tangent or parallel to the velocity vector? I'm confused because it can't be tangent and parallel at the same time,right ? I'd really appreciate your help here.
I am using tangent and parallel as meaning the same thing. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Oh got that Professor. I definitely recommend your channel to my friends. I belive my _Fluid Mechanics_ journey with you would be more easy for me. Can I ask some questions when I don't understand from here?
The height on both sides will go up, but the difference in height will not change, all else being equal. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Yes, really me. Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Con gusto! Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
is there an easy way to know when to use h or y as height? i keep associating the letter h with height and would automatically use it for my calculations, before realizing that it's actually y that i need to use
The actual pressure depends on h, the depth since pressure increases downward. However, you use y to determine where the average pressure acts and where the center of pressure is located. y is just the distance along the slanted line parallel to the plate since it is inclined. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Sometimes my wife accuses me of being like a robot - I guess engineers are just that way... Thank you for your comment. I am glad that my videos have been useful to you! Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Hi John, thanks you for the video. Two questions: 1) Why does max flow and 0 head correspond to 0 efficiency? I understand it is creating 0 head, but in my mind there is a non-zero kinetic energy generated by the fan when you turn it on, so it's still able to provide energy to the surrounding fluid (like a house fan for cooling). 2) Regarding the efficiency curve you plotted, what is the physical reasoning behind this curve? And does a high efficiency mean higher water horsepower, since the efficiency is expressed in terms of electrical power input which is constant?
If you think more in terms of a submersible pump rather than a fan it makes more sense. A pump sitting there in a bucket of water with no hoses connected to it will just suck in water and spit it back out without doing any useful work, defined as lifting the water to some head. There is zero efficiency because there is no head - no useful work done. The efficiency is defined in the video and is proportional to both the flow rate and the head. That is why it is zero on both ends. No flow but high head = zero efficiency. No head but high flow = zero efficiency. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
@@johncimbala Thank you for the reply John. I completely understand the perspective at which you are looking at the problem. You need to apply a force over a distance for work to be done. In the case of the submersible pump in your example, the pump is sucking liquid in and spitting that liquid out without generating any additional pressure to the suction pressure because it doesn't need to (it doesn't need to push against any additional load "downstream"). And this makes sense to me. What I can't exactly understand is the way we classify efficiency here. The energy required to rotate the pump has to go somewhere. Some goes as heat and other forms of energy losses, and the rest goes into providing the liquid with kinetic energy. Even though the liquid has 0 head, it still has the kinetic energy the pump gives it. If the pump wasn't running, the liquid wouldn't have the kinetic energy. So if we define efficiency as useful work/energy input, why can't the kinetic energy provided by the pump to the liquid be considered some form of useful energy? I feel like because the liquid is moving, it can be used for something - perhaps a jet for a hose? PS: Thank you so much for your videos. I have read your books on fluid mechanics and watched many of your videos. You do a great job making complex concepts look simple. You have an incredible knack for teaching.
@@sanjaysrinivasan2071 Interesting idea. One can argue that there is a "useful" result of generating a flow. Right now as I type this I have a fan blowing on me. It is doing something useful - keeping me cool! Technically there IS an increase in pressure from before the fan to after the fan, so it is doing some useful thermodynamic work, which is all turned into kinetic energy and then eventually lost as heat. Thank you again for your kind comments about my books, videos, and teaching.
@@johncimbala Right, that was what I was trying to get at. I agree that there will still be some work generated by the fan as it has to push through atmospheric pressure to flow to the user. Now that I think about it again, the efficiency definition makes sense. If I were running a pump at the max flow operating point, then I can't move it from one point to another because there is no delta P between the suction and discharge! No fluid displacement, just fluid recirculating within the pump. Not very useful of a pump, considering its application is to move fluid from one point to another. Thank you!
Not sure what document you mean... If you mean the annotated notes that I generated while recording the videos, they are all available on an Excel spreadsheet. Just look at the description and click on "...more" to see the link.
Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
Thank you for your kind comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
I always assumed the saying was a paraphrase of Isaiah 11:6 because it does say the lion will lie with the lamb, but they're not the only two animals lying together. The wolf, lamb, goat, calf, lion, and yearling will all lie down together, a metaphor for the peace that will abound on the earth. The saying was simply shortened to just two of the animals for brevity.
That may be true. I was simply pointing out that it never says directly that the lion shall lie down with the lamb - rather the wolf will lie with the lamb. Thank you for your comment. Please tell your friends and colleagues about my RU-vid channel where there are almost 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
@@StillYHWHs Show me a Bible that says this. I have not found one yet and nobody has been able to show us one. Thank you for your comments. Please tell your friends and colleagues about my RU-vid channel where there are more than 500 free videos about the Bible, fluid mechanics, science, math, Excel, statistics, air pollution, and other topics. I would greatly appreciate it.
