At ten feet underwater. . .

Question

Always wondered this. If you have a tube running to the surface perhaps 2" in dia. through which fresh air is introduced to a valved mouthpiece by which I mean you can breath out of a wye immediately to the water and breathe in only fresh air, so no admixing of gases, could you breathe? Not sure I understand the atmospheric pressure variance per every ten feet. Thanks

Answer 1

no. even if you get rid of the dead air space by exhaling into the water, you could not breath. the pressure is to great. why do you think snorkels are so short? the longest snorkel you can find is based on how deep you can breath if you were sitting upright on the bottom of a pool. there is a million dollar idea- 10 foot long snorkel. every one ate the pool would have them, so, why dont they make them? once your lungs are underwater about 2 feet, you cant breath. the thing that makes SCUBA work is the pressure of the air you breath increases with your depth. this is called pressure over ambient. i believe it runs at 14psi over ambient. SCUBA gear actually pumps air into your lungs. get a snorkel . sorry, but, that is all you get without pressurized dive gear.

at 10 feet the pressure will be roughly 6 psi.  that would place about 70 lb of pressure on your chest. it will take about 50lb (a guesstimate of the weight of water you displace by inhaling) more force just to pull the air down to you lungs. it will feel like a  300 lb person on your chest.

Answer 2

ya you can breathe because if the tube is going to the surface, and the valved mouthpiece is, of course, in your mouth. Kinda like a scuba diving thing, correct?

you'd not need an admixing of gasses because you're only ten feet under. not like thirty or something. lol. : 0

but yea. And probably the two inches in diameter would be good enough. Maybe maybe not. idk. I am not like a scientist or anything lol. =]

And I don't undersand the atmospheric pressure variance per every ten feet neither so, what the heck you know. Gotta take chances. Try it out yourself sometime maybe lol. You might be risking your life or something, but at least you tried ya know? Or maybe don't try that. Maybe you should try it, well wait. If you have 2 inches in diameter in ten feet, what if you had one inch in five feet. You don't need that much air because I bet you are taller than five feet and you don't need that much air again because you are close to the surface. Maybe try it in the pool or something. Wait, I change my mind lol. I do that a lot. =]

Just do two inches dia. in the five feet. If it works but not a lot of air comes out, I would try three inches in ten feet.

hope i helped! <3 Cali Gurl  

Answer 3

Check out the 2nd paragraph here:

http://en.wikipedia.org/wiki/Scuba_divin...

Basically, with what you're proposing, the deeper you go, the harder you'd have to suck in order to get the air to fill your lungs.  10 feet would probably be just fine, but it wouldn't work very well at, say, 60 feet.

Answer 4

The atmospheric pressure is a constant.

The pressure that you need to overcome is the WATER pressure.

In order to breathe, your body needs to counteract the pressure of the surrounding water in order to produce a vacuum which the air can enter.

What is your tube made of? The water pressure may collapse the tube and make air flow impossible.