I have a 160 mm water pipe at 5 bar pressure.What is the flow in litres per sec? I want to fit a hydro turbine to the outlet.
89638
Anybody kindly help me to find how to calculate pressure in bar from flow rate. I have a pipe and from that I am transferring water at a constant flow rate of 5ml/min. At this flow rate, with a 0.5 cm diameter pipe, what will be the pressure generated by water?
45513
A few days ago I noticed about a capful of water in the pail at the bottom of my water heater's TPR valve outlet.  This is the first time I've had any water come out of the TPR when I wasn't testing it.  I moved into this house in 2011.  In 2012 I installed a water expansion tank, with a ball valve to disconnect the hot water system—the expansion tank plus water heater.  I realize the water expansion tank is probably near the end of its life.  The water heater is electric and over 20 years old (I know), but I've been flushing it thoroughly once a year and replacing sacrificial anodes as needed, and it hasn't leaked yet.  The only recent change to the system is that I used to have a pressure gauge connected to a hot water faucet instead of the normal connection to my washing machine, and I finally removed the gauge and reconnected the hot water hose for the washing machine.  When the washing machine runs, I can hear a knock in the pipes when the washer hot water valve turns on or off (which was why I installed an expansion tank in the first place).  Note that there is a PRV on the water main.  To test things, I opened the TRP valve and closed it against.  It took its good old time closing and kept leaking for a while.  So I opened and closed it again, and that time it closed more quickly and stopped leaking.  I had seen this once before in testing, so I didn't read anything into it.  Then I closed the ball valve to remove external pressure from the hot water system, I opened all of the hot water faucets above it, and I checked the air pressure inside my expansion tank.  It's down around 28 PSI from the 60 PSI that it's supposed to be at, so I'll have to address that.  But when I opened the ball valve again and individually closed each faucet, the TPR valve spit out a bit of water again when I closed the last valve.  Am I correct in my assumption that the TPR valve is failing?  Is it normal for them to fail gradually instead of opening catastrophically?  Would the underpressured expansion tank have any bearing on this?
86888
Hoping someone can give me some thoughts on what might be going on here so I can be a bit more informed when I call a plumber.  Situation is, we got our water heater replaced a few years back and ever since this has been an issue. It's more noticeable when it's cold outside it seems, but still seems to be a year round problem. Whenever we  use hot water, we basically run out of it within minutes. In order to get an acceptable amount of hot water (enough to take a 10 minute shower), we literally have to prime the water first. By that I mean I have to turn on the hot water, let it run for a couple of minutes, then turn it off and wait 20 minutes. Then when we go to use the hot water again we'll get hot water for a respectable amount of time. Now I am fairly ignorant to all this, but it seems a 71 gallon hot water heater should be capable of holding enough water to not need to be primed like this. I should be able to take a 30 minute shower, let alone 10 without running out. My shower this morning was decently warm for maybe 2 minutes before it was just warm-ish.   So if anyone can give me some ideas on what might be going on I would appreciate it. We've just put up with this for some years assuming perhaps it was some eco friendly thing. Like the system doesn't maintain much hot water in the tank so it's not always running and only heats water up when you start to use it? I hope that isn't the case though and even so, I should be able to get more hot water out of it. Any help?  UPDATE Sorry everyone, I meant to tell you all that the water heater was gas. The pilot light is lit. I don't recall the specific model though I can look that up if people think it will help. I have actually turned up the thermostat on it above the default and when the water heater is putting out hot water, it can be very hot. Too hot. But again, that requires us to prime it before we get any decent amount of hot water out.  UPDATE 2 Looked it up, I believe this is the model info if that helps anyone: State Select: High Output. Model number: GS675XRRS 300
95050
the teacher gave me this problem to solve. So i hope you can help me with it. Here is the problem: John poured 150ml ob boiling water in 2 cups made out of polystyrene. Cups are open on the top so heat goes out there. Temperature of the outside air is 20°C. In 1 cup he add 5 mm thick layer of hot oil. He measured starting temperatures and then he measured temperatures again after 10 min. He measured the mass of water and water+oil before and after 10 min.  Here are the resaults:   -cup 1 (only water)  starting temp: 96°C  finnish temp: 64°C  starting mass: 149.4g  finnish mass: 142.42g  -cup 2(with oil on top)  starting temp.: 96°C  finnish temp.:91°C  starting mass: 164.72g  finnish mass: 164.70g  The surface of the both cups is 0.003 m2  Questions: 1.Why did the water covered with oil cooled down slower that the one with no oil? Show with calculations. 2.Why did John use oil with temperature around 100°C and not oil with room temperature? How would the resaults change if he used room temeprature oil? 3. Which other physical values, which are relevant, can you calculate from this informations? Basiccaly i need the physics behing why does this happen.
97571
I know this has been asked time and time again but bear with me as I am struggling to understand, so say I have this simple circuit here   with 120v (dc for simplicity) as the input voltage and I have an led that runs on 3.4v and max 20ma ohms law states I=V/R so R=V/I, so R=120v/0.02a = 6000 ohms or 6k is this correct? how do I know the voltage drop across the resistor is correct, and what about power dissipated by the resistor? also, Is there an easy way to calculate everything at once?
109087
I've been working on providing power for high current applications for my project. I'm working on a project with high current (or at least compared to what I'm used to...)  What a lot of people point to online is tables that you can look up the resistance for AWG per foot, and then you can calculate the current drop of your wire. However, with that current drop, how much of  a voltage drop will make my wire "too hot" and risk a fire? Am I looking at this the wrong way? How do I calculate the temperature of the wire and decide when it'll be too hot, and I should use a thicker wire?
5227
With the following circuits as examples :    and    How will the current I know how much to flow? Would any other wave travel first in the circuit and then come back and say so much current should flow?
71681
Poiseuille's law states that the rate of flow of water is proportionate to $r^4$ where $r$ is the radius of the pipe. I don't see why.  Intuitively I would expect rate of flow of fluid to vary with $r^2$ as the volume of a cylinder varies with $r^2$ for a constant length. The volume that flows past a point is equal to rate of flow fluid, and thus it should vary with $r^2$.  I cannot understand the mathematical proof completely. Is there an intuitive explanation for this?
36491
Hi I make this class A amplifier but how to replace R5 (10 ohm/10 W) with transistor because its getting really hot and how to achieve up to 10 Watt with +/- supply. I have +/-25v with 4A please help
85420
I've tried unscrewing the part outlined in red below. No dice. Do I just need to remove the whole rod (above the red outline) and replace it?) If so, can anyone point me to instructions for them.  I can't see in there. Worried that I'll pull it out and not be able to put it back in.  (The deeper I go in the plumbing the more things I find that there is no modern fitting-part :)  My new assembly  replaces the parts outlined in red. the new assembly has a female thread. I am HOPING that the thicker part of the pipe (just above the black "collar" stopper)  is screwed onto the pipe above.  However, I cannot unscrew it. There is nothing to get a hold of. It's perfectly round. I've tried dw40, and let it sit for 20 minutes. No love.  I'll try wacking it with a board in the direction along which it moves in when it screws (perpendicular to the threads per [this answer][2])
54609
Is the Ohm's law violated here? And also why is electricity generated at 11,000 V in India?
43576
It took me a long time to understand that current is constant throughout the circuit. And now I am stuck at one last thing: The speed of charge. Here is what I am thinking:  Current is defined as quantity of charge passing through a point at a given time, and from this we can deduce that current is constant throughout a circuit. But, if this is true, then wouldn't the speed of charge through a resistor be increased? Let us think about an analogy, water flowing through a pipe. Suppose water is flowing through a broader pipe(analogous to a less-resistance wire), and  a greater quantity of water can flow past a point because of larger cross-sectional area. Now, suddenly water encounters a smaller pipe(analogous to the resistor). So, less quantity of charge can flow through it because of less cross-sectional area. But, if the volume of water flowing in a time $T$(analogous to current) is same, won't the rate of flow of water in the narrower pipe(the resistor) be more?  I am asking this question because while seeing some answers for the question that "Why is current constant?" , I saw some people saying that speed of charge slows down a bit through a resistor, which seems incorrect to me.
23766
Is there a way to transport items upwards from, say, a monster trap? Water flow works fine downwards.
32417
I have an elderly person that is no longer able to walk the land to reach the faucet.  It's about 20' between the safe patio and the faucet.  She needs to turn on the faucet in order to hand water the garden (a task she enjoys so not thinking of using drip system).   My idea is to run a hose to the patio.  Then put a shut off valve there.  This means the hose and other equipment will need to be able to handle constant pressure for 3 months at a time in Texas.    Is there a hose and shut off that can handle this job?  My initial thought is a  and a .
71348
My basement apartment's hot water pipe runs starting with 3/4" from the heater to the first outlet, the bathtub and the 2nd one, the washer.  From the washer, it goes to the bathroom sink (please don't question this design as I have structural reasons why it doesn't go from the bathtub directly and don't want to spend time explaining as it's not pertinent) and ends in the kitchen sink, which will also be supporting a dishwasher.    My question is, can I run only  1/2" pipe for hot water starting from the washer, will it be enough bandwidth or should I go with 3/4" ?  I know that some people have up to 3 outlets out of a 1/2" copper pipe but I'm not sure how to count the DW as it is a different appliance but using the same valve from the wall inside the counter.  I have run 3/4 to the tub and to the washer and now I'm about to continue on from the washer towards the bath and kitchen sinks and need to make a design decision.
47215
I have the following ammeter:   The seller recommends 75mV 100A shunt be placed with it. I want to know what will happen if I change the voltage going through the shunt. Should I be changing the shunt as well to read amps correctly?   I want to build a 1-40V (or maybe 50V) adjustable DC power supply and use this ammeter to measure current. What the right value of shunt that I should use to get the right measurement? Changing shunts in a lab bench power supply is impractical, of course.  EDIT: I am planning to measure only up to 5A or so. Sorry I forgot to mention this previously.
21355
I am working on a project that requires the water to shoot out of the end of the pipe rather than what it is doing right. Now, I have played with some of the settings but am kinda afraid to mess with it too much since I am new to blender, and it does not play well when I mindlessly click.   Would I generate more fluid particles? Or would I change some property about the inflow animation? I added a cylinder object to the top of the pipe as well, I think that will help keep all the water inside of the pipe.   Thank you once again and have a great day!