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Hi I was reading with interest a page on the idea of a vertical pipe stood in a pool of water. I am interested in this subject. http://www.du.edu/~jcalvert/tech/fluids/hydstat.htm#Maxh
Does the column of water have any affect on the pressure at the bottom of the beaker it is standing in. For instance if a column of water was to be closed by a door from the liquid in the beaker, would the pressure of the water be changed. does the column of water have no affect on presure of water in the beaker it is standing in. I think this is an important scientific question and i can find no answer to it. It would be common sense that standing a column of water would mean a higher pressure excerted on the beaker, but is that not the reality. As the atmposheric pressure was already excerting pressure. Does anyone have the technological equipment to do this experiment. As i don't.
Does anyone have a watch barometer.

2006-11-10 01:21:07 · 3 answers · asked by acacaac a 1 in Science & Mathematics Physics

3 answers

If a lid was put on the water in the beaker and then the top of the tube was opened, then, in this case, the pressure at the bottom of the beaker would be increased.

In the original case, it is not increased.

One way of thinking of it: in the original case, the column is "supported" by the vacuum - but this is not usually considered the correct way of thinking of it.

A more correct way is to think of it is the atmosphere forcing down on the surface of water in the beaker, and this forces the water up the tube.

The pressure on the bottom of the beaker is equal to that of the atmosphere (A) plus that due to the depth of the water in the beaker (B).

The pressure on the bottom of the beaker is also equal to the pressure at the top of the water in the tube (zero pressure) plus the pressure due to the column of water above the level of the beaker (also A) plus that due to the depth of the water in the beaker (B again).

So both ways give A + B.

Another way of thinking of it is thinking of the water pressure decreasing as you travel upwards from the bottom of the beaker (at A + B). When you get to the level of the surface of the water in the beaker, the pressure is A whether you are inside the tube or outside. If you travel up the tube then the pressure becomes less than atmospheric - until you reach zero pressure at the top of the water column.

2006-11-10 10:54:08 · answer #1 · answered by Frank S 2 · 0 0

I guess I don't understand the relationship between the link you gave and what you're asking. Or maybe I don't understand what you're asking.

If the pipe is open at the bottom and top, the water will run out.

If it is sealed at the bottom, the pipe must be supported by the bottom of the beaker or maybe a bracket suspending it into the water. In either case, the water in the pipe is supported by whatever is supporting the pipe. The sealed water wouldn't contribute to the pressure of the independent water in the beaker.

2006-11-10 06:32:19 · answer #2 · answered by sojsail 7 · 0 0

i'm going to assume that with the help of 'suspended' you advise which contain putting with the help of a thread from above the beaker, and likewise that the gold ball is thoroughly submerged. if that's the case then the mass of eh beaker -water device could be better with the help of a mass equivalent a quantity of water equivalent to the quantity of the gold ball. gudluk

2016-12-28 17:54:26 · answer #3 · answered by ? 3 · 0 0

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