Why can't scuba divers just take a long hose with them from the surface and breathe through it? I know it's something about air pressure, but I'm not exactly sure...
2007-02-27 11:10:41 · 6 answers · asked by Anonymous in Environment
If your hose were too long, you would eventually inhale that which you are exhaling as the exhale would not make it to the exit of the hose.
2007-02-27 12:01:13 · answer #1 · answered by Christmas Light Guy 7 · 0⤊ 0⤋
Pressure isn't the only problem - Even snorkels can't be much longer than about 18" because the volume of air when you exhale has to clear the snorkel entirely, or you breathe back in your own air (which has no oxygen in it) and you suffocate.
Hoses are used for deep sea diving, but the air in the hose is pressurized so fresh air in moves in from the hose, and used air is exhaled into the water. Deep sea divers have to use hoses because the tanks don't last long enough to decompress on the way up. The pressure at the breathing end of the hose goes through a regulator valve, just like scuba tanks, so the pressures are equalized.
2007-02-28 11:33:08 · answer #2 · answered by formerly_bob 7 · 0⤊ 0⤋
Hi... all realy good answers given. . It just seems like it would work though, huh? So much of it does have to do with pressure. And a lot does have to do with 'used' air. A regulator does all of the work for you. You breathe, in fresh air from a tank...or from a surface air source, BUT the regulator exhales the used air for you, so you are not rebreathing the same air. The air that you are breathing in is about 21% oxygen, and when you exhale, the oxygen has been depleted down to about 16/17%. It is very important to get rid of that 'used' air. There are other considerations. Not only does the pressure exerted on the hose and the air inside make it extremely difficult for you to inhale from that hose, but the surrounding water pressure could actually collapse a hose not designed specifically to feed surface air to a diver below. :-)
2007-02-27 20:28:41 · answer #3 · answered by reesiebutterfly 1 · 0⤊ 0⤋
Try it some time in a pool with a garden hose. I did once. The deeper you go the more water pressure squeezes your body, so you have to use more muscle power to expand your lungs and draw in the air. In terms of physics, the pressure of the air in your lungs has to be lower than the pressure of the outside air in order to draw in more air. If the hose is strong enough to not be squeezed flat by water pressure, then air in it is just at the normal 32 psi of surface air. But you under 10 feet of water are experiencing 42 psi of pressure, 32 from the air and an extra 10 from the 10 feet of water above you. Scuba gear feeds air at the same pressure as the surrounding water by means of a regulator and a high pressure tank.
2007-02-27 19:56:15 · answer #4 · answered by campbelp2002 7 · 0⤊ 0⤋
It has to do with air pressure and air circulation. CO2 is more dense than air. That means that CO2 settles into lower places - places like the deep end of a submerged hose.
2007-02-27 19:41:30 · answer #5 · answered by physandchemteach 7 · 0⤊ 0⤋
You can.. it is called SNUBA. It has limits on length, though.
Commercial divers, too, get air supplied from the top.
But it does involve using a 2nd-stage regulator and 1st stage so the air being delivered is at the same pressure as the water.
2007-03-03 12:54:48 · answer #6 · answered by Anonymous · 0⤊ 0⤋