# Search results

1. ### Gas Law Calculation

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.
2. ### Gas Law Calculation

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.
3. ### Gas Law Calculation

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

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

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

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...
7. ### Gas Law Calculation

[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...
10. ### How to calculate torque on a shaft?

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...
11. ### Transposition Help

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.
12. ### Transposition Help

I'll be perfectly honest. I have no idea what you mean.
13. ### Calculating heat

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...
14. ### Transposition Help

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...
15. ### Transposition Help

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?
16. ### Calculations for heat transfer between fluids

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...
17. ### Shaft Speed Calculation:

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.
18. ### Shaft Speed Calculation:

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...
19. ### Puck Launcher Calculations

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?
20. ### Puck Launcher Calculations

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...
21. ### Puck Launcher Calculations

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.
22. ### Puck Launcher Calculations

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...
23. ### Puck Launcher Calculations

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...