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So the pressure is 200Pa gauge or 101525 absolute @ 22'C or 295Kelvin. I'm trying to find P2 after a 1'C pressure drop so 21'C. P2 = P1*T2/T1 therefore P2 = 101525*294/295. The answer for that is coming out as 101180.85 absolute or -144.15Pa gauge.

So this appears to make a fairly big difference, unless I'm doing something wrong. Results: 200Pa @ 22'C -144Pa @ 21'C -488 @ 20'C -831 @ 19'C So fairly substantial changes there.

What about pressure? Do I have to use absolute... e.g. 200Pa gauge is 101525Pa absolute (assuming atmospheric pressure is 101325Pa)?

Okay thanks. One last question and sorry to be a pain, what units should I be using? I'm assuming temperature in kelvins right?

So I should be able to calculate my constant and work backwards from that to see how pressure changes as temperature does.

Sorry, I probably should have been a bit more detailed and specific. The 1m X 1m X 1.5m chamber is empty (other than the air) and positioned in a room that is currently 17'C. The room is also positive 30Pa to atmospheric. The chamber is temperature/humidity controlled and sits at 21'C and when...

[Moderator's note: Recategorized thread to "Basic".] I'm having an issue at work that I think may be down to temperature. I have a sealed chamber that is 1m X 1m X 1.5m. The chamber has to be pressure tested but the results are all over the show. The only variable is temperature. So my...

Thanks for the reply. So do you think a single pass through a 1m long coil could produce the same amount as multiple passes through a 0.1m long coil?

So I have a very basic question, but I have next to no electrical understanding so can't answer it myself. With a Faraday torch you shake a magnet in a coil to create electrical charge. They say the harder you shake the more charge you create, so my question is this... is it the increased...

I have designed and built a steam powered turbine that I am trying to get to run a compressor. In order to choose a compressor I've been trying to calculate how much torque my turbine is producing. The only figures i have are... RPM - found using a tachometer Combined weight of turbine blade...

The first one was correct yes. So the first reply by mathman was correct. Thanks for your help guys, and sorry for posting in the wrong section.

I'll be perfectly honest. I have no idea what you mean.

Im trying to calculate how hot the gas inside my exhaust pipe is. I have several numbers and a calculation on how to find heat transfer, but no way of finding inside temperature if i don't already know it. Length= 0.5m k (heat coefficient for stainless steel)= 25 Internal Diameter= 73.2mm...

In it's actual form it's: Heat Transfer = ((2 * pi * heat coefficient * length) / Ln(Outside Diameter - Inside Diameter)) X (Inside Temperature - Outside Temperature) That gives you heat transfer. My problem is i know all the figures for one end of the pipe to give me an answer. But I'm...

Just need a bit of help with this. A = ( ( 2 X pi X k X L ) / (Ln(1.041) ) X (D - E) I know everything except D. How do i find it?

Im working on a little project where I am attempting to generate steam from a hot gas pipe. I haven't measured the rate of flow or temperature of the fluid as of yet, and I haven't decided upon the choice of material, but I'm looking for some calculations to start. My plan is to wrap a water...

Yeh that's the answer I had as well. I just thought it seemed too simple to be the same principle as gear ratio's. Thanks for your help.

I am trying to figure out the speed that a motor shaft is running at but i have no reference materials to work with. I had to place a tachometer on the outside of the shaft as there was no centre drilled hole to work from. I got the following results: Diameter of tachometer: 31.5mm Diameter...

Yes, but remember the wheels have a force acting upon them which is going to try and stop them spinning. So surely if the motor has 0.00001lbs-ft of torque, the wheels would just stop spinning as soon as the puck makes contact?

Ok so I am back to this. I've been working on some calculations today and i know how to work out the torque I am getting and the surface speed of the wheels. One thing i need to know is torque required and i noticed a tennis ball launcher on this forum where someone needed the same thing. The...

Yeh i think you are right. That's probably the best way to go about it and i know the examiners will love that sort of thing. Thanks for all your help and fingers crossed my project will all go to plan.

Thanks for the welcome. The problem is I don't know about the torque applied to the puck. I only have a basic knowledge when it comes to torque and speed calculations. All i know is the torque of the motor and the rpm at this point. I haven't gone into detail on any gearing or anything yet as...

Hi, for a project at college i am building an ice hockey puck launcher for the development and training of ice hockey goaltenders. I am planning on using two wheels rotating in opposite directions to launch the puck. The pucks will be fed in by a pneumatic cylinder that is powered by a...