OT Hypothetical question for the Group

Greetings all,

The following question was raised at work today, thought someone here might be able to answer it definitively, possibly even with some of that fancy math I have heard so much about. (G)

On the floor we have a 5 gallon bucket full of water. Suspended 5 ft. above said bucket we have 1 Quart of water, a tube, with a valve in it, is attached to the bottom of the quart jar and terminates at the bottom of the

5 gal. bucket. For argument sake the tube is full of water and actually terminates 1 tube diameter above the very bottom of the bucket, should be no restriction of flow.

The Question; If the valve is opened, will the water flow from the quart jar into the bucket?

The general opinion is that the water will not flow due to the fact that it cannot "push" the ~5 gal. of water up.

Possible Variables; The tube has no water in it. The tube size set at 1" ID. (I realize this could be a very big variable, allowing that if the tube was 6" ID and holding water it could easily hold more water than the bucket could hold.) The quart jar and the 1" ID tube are raised to a height so that it can build sufficient head pressure to flow into the bucket, how high would that be?

Thanks in advance for any and all help, feel free to point out any other variables I may have missed.

Regards, Jim

Reply to
Jim C Roberts
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"Jim C Roberts" wrote: (clip) If the valve is opened, will the water flow from the quart jar into the bucket?(clip) ^^^^^^^^^^^^^^^^^^ Water seeks its own level. Water will run out of the one-quart jar into the

5-gal bucket. Since you say the bucket is full of water, one quart of water will overflow the bucket. The jar and tube will wind up empty. You will get the same result no matter how far the tube extends into the bucket.
Reply to
Leo Lichtman

In this type of situation, the volumes such as "quart" and "5 gallon" have nothing whatsoever to do with the problem. Height is the only thing that matters. The pressure of 5 feet of water above another water surface of will empty into the lower water if the tube goes to the bottom of the ocean. If there is an open path and no external pressures, water will always "seek its own level". In other words, the water that is higher will flow downward.

This would be easy enough to try as an experiment.

Don Young

Reply to
Don Young

Jim, I strongly suggest that this hypothetical experiment NOT be attempted without a hypothetical mop handy otherwise its going to get hypotheticaly messy. :(

H.

Reply to
Howard Eisenhauer

The only way some of that water stays up is if there's an airtight lid on the quart jar, else that quart is all over the floor.

Didn't you ever siphon gas?

GWE

Reply to
Grant Erwin

Would the quart of water be in a vented container? Would the quart of water in an unvented 1 quart container?

If it is vented, it will flow.

Jim

Wudsracer/Jim Cook Smackover Racing '06 Gas Gas DE300 '82 Husqvarna XC250 Team LAGNAF

Reply to
Wudsracer

Just curious, where do you work?

Reply to
Pete Keillor

I have a bizarre guess (would love to know real answer)

A non running engine is sitting there full of oil. The pickup screen for the pump is at the bottom of four quarts. Oil channels stay full above it because of a check valve of sorts. so I am guessing with this question it would flow if top quart was vented. although if the pressure at the bottom of five gallons was greater than weight of example above, it should just sit there and not flow? what if the quart was hot and the 5 gallons cold... I wonder what size tubing would stop flow... what of the five gallons was warm and the quart ice cold... Now I have confused myself

*yawn* naptime, brain cells overloaded.

This question seems so familiar..

Reply to
bgd

Tell me about it...........

Thanks to all who answered, guess I/we were over thinking this one. Boy, don't get accused of that very often. :)

Regards, Jim

PS Pete, I work at a fab. shop in Chattanooga, Tn. Bring on the dumb redneck jokes.

Reply to
Jim C Roberts

You seem to have forgotten about gravity, which is a constant. The water will end up in the 5 gallon container. Or the floor.

Reply to
mb

In order for the water to fill the bottom container, air would have to take the place of the water in the top container. Assuming the top container is not vented, where would the air come from? The whole answer depends on if the top container is vented or not.

Dixon

Reply to
Dixon

It wouldn't flow if the valve was replaced by a hehnway.

Reply to
Stupendous Man

Is this water in a liquid, gaseous or solid state?

How close to the Earth are these containers?

What is the ambient temperature and atmospheric pressure?

Is either or both containers in motion?

There is more to this question than meats the aye...

DJ

Reply to
IdaSpode

Everything is "in motion". The question should be, what is the motion of the comtainers relative to each other.

Jon

Reply to
Jon Danniken

"Jon Danniken" wrote: Everything is "in motion". (clip) ^^^^^^^^^^^^^^^ The statement, "Everything is 'in motion'" is relatively meangless.

Reply to
Leo Lichtman

If the pressure were greater in the 5 gal bucket, it would flow out of the bucket. If it were equal, it would not flow.

Water pressure is a function of depth, not hose size or bucket size. So the pressure at the outlet at the bottom of the 5 gal bucket (if you put a pressure gage on it), would be based on how high the top of the water in the bucket was from the gauge, and (almost) nothing else.

You would see the same pressure on the gauge if instead of a 5 gal bucket, you only had a 1/2" vertical tube with water at the same height.

Because the quart jar is higher, the pressure in the tube leading up to the quart jar is higher (at the bottom where it connects to the bucket), so water starts to flow from high to low pressure into the 5 gal bucket. Once the water in the tube drops to the level of the water in the 5 gal bucket, the pressure at the bottom of the bucket, and the bottom of the tube become equal, and the flow stops. The water in the bucket and the tube end up at the same height.

Liquid water expands when it's hot which makes it less dense so the hot water wouldn't be as heavy so when the water stopped flowing, the water level in the hot tube would be slightly higher. I suspect the difference would probably be so slight you wouldn't be able to see it.

Let see...

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1 deg C water has a density of 1002.525 kg/m^3

99 deg C water has a density of 961.592 kg/m^3

So the height difference would be the ratio of these densities (I think). So if the water was 2 ft deep in the bucket, it would 2 ft 1.021" in the tube so I was wrong - it would be easy to see for ice cold water in the bucket and almost boiling water in the tube.

Who wants to do the experiment and report back? If you just create a U shaped pipe, fill it with ice cold water, and then heat up one side with a welding torch (required reference to welding in post) you should be able to see the water in the hot side rise and the water in the cold side drop up to 1/2" for each foot of pipe.

Reply to
Curt Welch

Reply to
David Packer

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