one for snownan

If water is pumped rapidly through the pipe as shown, it will rise

[] Higher in tube A than in tube B [] Higher in tube B than in tube A [] In tube A only [] In tube B only

|A| |B| | | | | _______| |____| |____________

--> ________ -->

___________/ \________

I answered "In tube A only" and got it wrong. It's like the vacuum apparatus we used in chemistry lab. Always bothered me to watch that water go right down the drain.

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Reply to
Beryl
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I assumed both tubes vented to air. If water is "rapidly pumped" through the main tube, it's pressure will be high as compared to the air, which means that it will look for any exit point The venturi will lower the pressure thus, higher in A than in B seemed like the correct answer

An interesting experiment would be to fill the system with mercury, make sure that tubes A and B were over 33 inches long, cap tubes A and B, and ensure that the main tube had a reservoir at least 33 inches high. The level of the mercury in tubes A and B and the main reservoir open to the atmosphere should be the same. Then turn on the pump and measure the height of the mercury in tubes A, B and the main reservoir. I guess that the level in tube A would drop, the level in B would drop more that in A, and the main reservoir would rise.

Reply to
Frank Will

How about leaving tubes A and B open to the atmosphere? Would there be a difference in the heights of the mercury in the tubes?

Reply to
Frank Will

You draw this one.

Looks like they do, nothing says they don't.

Why?

It's a carburetor. B sucks gas unless the float bowl's empty. Then it sucks air.

Reply to
Beryl

Something has to move the water through. It's going through a horizontal tube, so it's not gravity moving the water, it has to be pressure. If it were atmospheric pressure, it wouldn't move, because the pressure at the inlet and out let would be the same. I think.

I'm thinking about my garden hose and sprinkler system. Granted, there are no venturis in it (I hope), but when one sprinkler breaks off, a lot of water comes out that pipe, but the other sprinklers still have some coming out.

Correct me if I'm wrong, but a carburator has air flowing past the venturi and draws liquid gasoline, not the other way around as in the question. If you turned the whole thing upside down and put the small tubes in water it would be more like a carburator.

I think this is a great experiment to run with my grand daughter. This can easily be made out of PVC, and clear hose. I can also show her how blowing across the top of a piece of paper will cause it to rise. I'll have to find a few more experiments we can do before her family comes for Thanksgiving.

Reply to
Frank Will

What if the pipe spun around its inlet end, like a centrifuge, sucking water up into the inlet, thru a 90* elbow, then flinging it outward? ____________________________ / / --->

/ _________________________ / / | | | | | | /\ | |

We better get punkin's opinion on this.

Break *all* the sprinkler heads off and see what happens.

The aspirator thingy works on an air line too. The wikipedia article says you can create stronger vacuum running a gas thru the aspirator than a liquid, due to the vapor pressure of a liquid.

Break all the sprinkler heads off and show her what happens.

Reply to
Beryl

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