Breathing from a 30ft. snorkel

[redacted]

Actually we do not suck the water up the straw. We remove the air pressure from the inside of the straw and the atmosphere forces the water up the straw. If you tried the same experiment with the cup being pressurized the results would be different

And how do we remove that air pressure? Are you looking to correct the english or the science?

 

[Guba]

Yes, the dilemma is in the semantics. In the context of my previous posts, "suck" is differentiated from "inhale" solely according to the muscle groups being used. The physics of the water moving up the tube is a function of the resulting air pressure, of course.

 

[Cave Diver]

You should have no trouble expanding the bottle. The air in your lungs is at ambient having been delivered from the regulator.

A better analogy would be to blow up a balloon that has a resistive force of 28 psi on the surface.

If I recall correctly, most people can't blow more than about 5-6 psi of pressure.

It also looks as if about 5-6 psi is the max amount of pressure that can be overcome by blowing, with the average around 2-3 psi.

Think it's back to that "blow up a balloon with high resistance experiment."

Maybe we could put a balloon on a long tube and blow it up. Then put the balloon underwater and see how deep it has to be before we can no longer blow it up?

I might be able to try this later in my sisters pool.

Ok, so I just tried this experiment.

I borrowed a balloon from my nephew.

Standard latex(?) balloon, from some sort of fair they attended recently. Inflates on the surface to about the size of a dinner plate. Blue if it matters to anyone.

Put the balloon on the end of a piece of PCV pipe. 1/2" inside diameter, approximately 4 1/2 feet in length. Was able to inflate the balloon at the surface with no problem to diameter of dinner plate.

Placed the balloon/pipe into the water to the bottom of the pool. Measured right around 44" deep (above ground pool). Attempted to inflate and had great difficulty. After several attempts, including holding the pipe at a slight angle (in case the neck of the balloon was pinching closed as it tried to float with the air) I was able to inflate it to roughly the size of my closed fist.

This was basically enough air to make the balloon take shape, with only a very slight expansion of it and I was only able to inflate it to roughly 1/5 of the size achieved at the surface.

Repeating the experiment at ~2' depth yielded better results, maybe half full balloon. Still unable to achieve full inflation until I brought it back to the surface.

My very non-scientific conclusion: If I can't inflate a balloon using my diaphragm muscles/exhaled breath from my lung at 4' of depth, then it's highly unlikely I can inflate my lungs using a snorkel at that same depth.

YMMV.


Guess I don't have as much hot air as some of you think.

 

[ScubaSteve]

Blue if it matters to anyone.

Well there is the problem

Guess I don't have as much hot air as some of you think.

I still say that is up for debate

 

[Atomic_Diver]

Is this not the same idea as taking a (for ex) 20' long garden hose, cutting it, and trying to breath from it at the bottom of a 10' deep pool?... Sorry not going to work- heres an expirment for you: take your snorkel in a pool to the shallow end, try to put your entire head u/w, so that the snorkel tip is just barely enough above the surface so as to keep water out, and try to breath from it... Hard isn't it? Now tell me what makes someone think that taking a 30' long hose u/w that they can breath from it by just sucking air all whe way down, it would be like sucking a cat through a straw..

 

[Cave Diver]

Well there is the problem

It was a Canadian balloon. It was blue because it was cold, eh? :cold:

 

[tregrrr]

...I borrowed a balloon from my nephew.

....

Guess I don't have as much hot air as some of you think.

before you give the balloon back to the nephew, do you have a niece, daughter, or neighbor's kid preferably in the 13-18 yearold range?? such a demographic has shown significant promise as a natural hot air resource, as researched and targeted by cellular telephone marketers....

 

[Guba]

Ah, but with the advent and subsequent progress of texting, the hot air factor is rapidly being reduced in the said demographic. Provide a finger-driven handpump, and you're in business!

 

[ScubaSteve]

.....it would be like sucking a cat through a straw..

But why would someone want to do that? Nice comparison...thanks for the laugh.

 

[Atomic_Diver]

But why would someone want to do that? Nice comparison...thanks for the laugh.

Meow, don't know