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Getting wet in my leaky suit
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Discussion Starter #1
yes I know I'm gluten for punishment :tongue: and i know the top three threads in here have been started by me :)

but could anyone explain the basics and formula behind boyles law?

or at least recommend a website that would explain it? (wikipidea (sp?) confuses me :D )


cheers in advanced :)


liam
 

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Getting wet in my leaky suit
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1,405 Posts
Discussion Starter #3
Erm . . haven't you just done your physics exam? :star:
i did a gcse level one but that only covers things like voltage, gravity, forces ect :) boyles is a higher grade :)
 

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Nigel Hewitt
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7,142 Posts
yes I know I'm gluten for punishment :tongue: and i know the top three threads in here have been started by me :)

but could anyone explain the basics and formula behind boyles law?
You have a quantity of gas.
You have to wait for it to return to the same temperature after you do things becuase we're assuming the temperature doesn't change.

Boyle says: Pressure multiplied by volume is a constant for that quantity of gas.

eg:
Two cylinders with 150 bar in the 12L one and 50 bar in the 10L other.
You connect them together.

150*12 + 50*10 is the sum of the two constants so you started with. ie: 2300 somethings.
It is now in 22L worth of cylinder.
so P*22 = 2300
so P = 104.5 bar

Is that what you wanted?
 

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Getting wet in my leaky suit
Joined
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1,405 Posts
Discussion Starter #5
You have a quantity of gas.
You have to wait for it to return to the same temperature after you do things becuase we're assuming the temperature doesn't change.

Boyle says: Pressure multiplied by volume is a constant for that quantity of gas.

eg:
Two cylinders with 150 bar in the 12L one and 50 bar in the 10L other.
You connect them together.

150*12 + 50*10 is the sum of the two constants so you started with. ie: 2300 somethings.
It is now in 22L worth of cylinder.
so P*22 = 2300
so P = 104.5 bar

Is that what you wanted?
looks about right :) cheers for that
 

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Getting wet in my leaky suit
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1,405 Posts
Discussion Starter #8
Don't PADI teach this, BSAC do very early on :)

padi teach the basics of pressure at ow level... but the science behind it kicks in at divemaster level :)
 

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Getting wet in my leaky suit
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1,405 Posts
Discussion Starter #12
I can't beliveve this isn't covered in GCSE level physics.
i can

Ditto.

Bring back the good 'ol days (hmmm, maybe not)

DC

Having seen a foundation level GCSE science paper, I can.

agreed... even the higher level gcse physics paper had all the formulae typed all over it, kinda makes you want too say they're getting easier.... but they're not ;)

i cant believe my 1,000th post is spent arguing the case of gcse's, -sigh-
 

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Nigel Hewitt
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7,142 Posts
The Feynman Lectures on Physics

everything you wanted to know about everything.
 

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Wreck Ferret in training
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566 Posts
Boyles Law : P1*V1 = P2*V2

ie double the pressure = half the volume

or to put it another way, use 20 litres a minute on surface then when at 30 meters where pressure is 4 bar you will use 80 litres a minute
 
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