Re: [Phys-L] fluids

["Lulai, Paul" <plulai@stanthony.k12.mn.us>]

The flow in the pipe is different at the intro level.  We (intro level)
generally assume that the pipes will be full and that there is a large
enough reservoir that the pipe will always be full.



Paul Lulai
Physics Teacher
St Anthony Village Senior High
St Anthony Village MN 55418


On Thu, Feb 7, 2019 at 12:01 PM Anthony Lapinski <alapinski@pds.org> wrote:

> As a stream of water falls from a faucet, the stream narrows. I've heard
> this is due to continuity -- A1v1 = A2v2. The water accelerates as it
> falls, so the area decreases.
>
> But isn't continuity for fluids in pipes/hoses, etc? As the area changes,
> the velocity changes (not the other way around).
>
> I thought the stream narrows because the air pressure is slighter larger at
> the lower height (P2 = P1 + pgh). But it seems the air pressure hardly
> changes in a few centimeters to cause the stream to narrow.
>
> Or does the surface tension in the water cause it to remain intact as it
> falls, acting like it's in a pipe?
>
> --
>
>
>  <http://www.pds.org>
>  <https://www.facebook.com/princetondayschool>
> <https://twitter.com/PDSPanthers>
> <https://www.youtube.com/channel/UCVE-nTva0BlK0rT6vayqpIQ>
> <https://www.instagram.com/princetondayschool/>
>
>
> *CONFIDENTIALITY NOTE:*
> The information transmitted, including attachments, is intended only for
> the person(s) or entity to which it is addressed and may contain
> confidential and/or privileged material. Any review, retransmission,
> dissemination or other use of, or taking of any action in reliance upon
> this information by persons or entities other than the intended recipient
> is prohibited. If you received this in error, please contact the sender
> and
> destroy any copies of this information.
>
>
>
>
> Please consider the environment
> before printing this email.
>
>
>
> _______________________________________________
> Forum for Physics Educators
> Phys-l@mail.phys-l.org
> http://www.phys-l.org/mailman/listinfo/phys-l