Archimedes Schmarchimedes

[Kirstie]

See, it's all so simple really.

So why can't I 'get it'?

I'm more of a visual person. I might have to go home and draw it.

[Woz]

Would it help if I described it in terms of fluffy kittens and knitting patterns? Do you need help reverse parking your car?

[Finless]

Originally Posted by Kirstie

See, it's all so simple really.

So why can't I 'get it'?

I'm more of a visual person. I might have to go home and draw it.

Have you offended the Turbanator? Try some kinky underwear ..... or no underwear ..........

Go gentle if you are doing a rubbing!

[Kirstie]

Originally Posted by Woz

Would it help if I described it in terms of fluffy kittens and knitting patterns? Do you need help reverse parking your car?

NO!

How about ice-cubes floating in a gin and tonic. Or lime wedges in a bottle of Corona?

[dublinbay]

Originally Posted by Kirstie

I think I understand that bit. It's the order of the calculations that throws me. You know, the multiplying by 1.03 for sea water and 1 for fresh water, the volume of the object minus the displacement, the age of Archimedes divided by the gross annual olive crop etc etc.

Surely, in the real world, if you have to lift an object from the seabed, you take down the biggest liftbag you have, fill it completely full of air and let it go? Do people really sit about calculating how much air they need to the nearest bar? Do they buggery!

The DIR chaps do. Hence the smaller wings on twinsets. If your kit and weights are 28lbs/14 kg negative(with full tanks) all you need is a wing that will lift 28/30lbs. Part of the balanced rig idea. Simple schmimple

[Kirstie]

Originally Posted by Finless

Have you offended the Turbanator? Try some kinky underwear ..... or no underwear ..........

Go gentle if you are doing a rubbing!

A rubbing? I'm doing the mapping project on Sunday. I could do a rubbing of Le Poulmic.

[David G]

Originally Posted by dublinbay

So to achieve neutral buoyancy with Woz`s 11kg of lead you need a 10 litre lift bag (10 ltr = 10kg of lift + 1 kg of upthrust =11kg )

and then if the block of lead is at 20m, where the Absolute Pressure is 3bar you will need 10 litres* 3 Bar = 30 litres out of your cylinder to fill the liftbag....

Do you need this step too?

[Kirstie]

Originally Posted by David G

and then if the block of lead is at 20m, where the Absolute Pressure is 3bar you will need 10 litres* 3 Bar = 30 litres out of your cylinder to fill the liftbag....

Do you need this step too?

Well, I think I do, probably. Depth was mentioned on a few of the workbook examples but Fraser and I (we were sharing a calculator) decided to ignore that bit of the question.

[dublinbay]

All said and done, I have managed an upthrust of 80 kg on regular occasions. At the moment its receded to about 4 kg owing to various DCI side effects........................................... ........

[Kirstie]

Originally Posted by dublinbay

All said and done, I have managed an upthrust of 80 kg on regular occasions.

Congratulations

Most of the time, diving in Plymouth Sound and its environs, I can barely raise a smile, let alone a 20kg object.