Re: The things people build out of PVC nowadays...

Logan Shaw <lshaw-usenet@xxxxxxxxxxxxx> writes:

> While I see your point, wouldn't this same argument apply to a hole
> in a dam? If the pressure isn't allowed to build up, then the water
> should flow out at the same rate regardless of whether you make a
> hole at the bottom or the top of the dam. But we know this is not
> the case; if the hole is nearer the bottom, the water squirts out
> faster because it's under more pressure.

If you aren't getting a lot of frictional loss in the pipe due to
turbulence etc., then the pipe contains a column of water that is more
or less in free fall, hence pressure can't develop with depth.

In the case of the hole in the dam you have a largely-contained mass of
water escaping from the hole at a rate relatively negligible to the
amount of water contained.
.

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