Re: The recoil of a hose when the tap is suddenly opened

Y.Porat wrote:
Sue... wrote:
Tareq wrote:
Let's assume that the hose recoils for the same reason that a rocket is
pushed by the propulsion of gases or a small balloon filled with air
moves fast when a small hole is made in it. But from the very
microscopic level, why is the balloon pushed or how does it know that
air is flowing out?

Hello
When you open a tap connected to a hose suddenly you see that the hose
will recoil in the other direction of water flow. Why? I know that the
direct answer is the conservation of momentum, but the water and the
hose are very loosly connected and conservation of momentum requires- I
think- a force mediator (either a force field like electromagnetic
field or a physical contact) between different objects for such
phenomenon to happen between them.

How does the hose know that water started to flow??

Think of it this way:
It is much easier to accelerate the lightweight hose than
the water inside the hose. So if degrees of freedom exist
for the hose to move and the water to remain ~stationary~ ,
that the how the system will balance its reaction forces.

It is the path of least resistance, poetically speaking.

Sue...

---------------------
you forgot to add that is with consistsncy withthe laws of God (of the
Lord !!)
(:-)

It is NOT consitant in that respect. If you perform an experiment
inside of Soloman's temple, pi will be 3 instead of 3.14 and
all your circles will go whorlly. (whorlly is a new word I just
learned for a flyball governor) Soloman was a King, not
a Governor so had no use for flyballs.
http://www.recoveredscience.com/const303solomonpi.htm




and how about:
a simple momentum effect ???

Does my use of the word "accelerate" in some way
ignore momentum ?

http://www.glenbrook.k12.il.us/gbssci/phys/Class/momentum/u4l1b.html


we learned about it at the secondary school .

The URL above appears on that level.

and btw
it is the same principle of the jet engine.of our modern airoplanes

No... they work like wood screws. They screw their way through
the sky. Their blades even have a pitch. :o)

http://en.wikipedia.org/wiki/Propeller
http://en.wikibooks.org/wiki/Jet_Propulsion/Jet_engine_types

Sue...


anyway a remark to PD
welcome to the** simplicity** club!!! (:-)
you are a new member there !!

ATB
Y.Porat
-------------------

.

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