Water Pressure?

Question

If you have a pipe with constant cross-sectional area and water is flowing from point a to point b, in which point b is elevated with relation to point a, at which point is there more pressure? a or b? and why?

Answer 1

There are two components to the pressure in the pipe. First is the pressure due to gravity. Lets assume for a moment that the pipe at point "b" is open, that is that the water flows out of the pipe at that point. There will be no pressure at point "b" due to gravity since there is no water above point "b". On the other hand, there is pressure due to gravity at point "a", as a result of the water in the pipe above point "a".

Now we consider the component of pressure due to the water flowing from point "a" to point "b". As long as there is no friction between the pipe and the water (which of course there is in reality), the pressure due to the flow will be the same at point "a" as it is at point "b".

So, altogether, the pressure at point "a" will be higher, solely due to the "weight" of the water in the pipe pushing down on it.

Hope this helps.

Answer 2

There will be more pressure at point a since the water in the pipe has potential energy (pressure) proportional to the height of the column.


Doug

Answer 3

the lowest point would have more pressure, releasing more water if it were to burst.

more water will almost always come from the lowest point. But if u were to channel that water to a higher release point than point b then point b would then start to release more water as it is lower...

I guess it has something to do with gravity and origin of pressure.

Answer 4

The "head" is greater at the lower point.

a point is lower, so the weight of water, at this lower point will be greater. (greater head.

William