Pumping water with atmospheric pressure

[JamesBe1]

I think the flaw in the reasoning is in the statement "A very interesting point here to note is that work input to the system in only energy supplied to overcome friction between tube V2 and rubber ring . . ."
This is simply not the case.  The real energy input to the system is the energy required to overcome the friction of the o-ring plus the energy to overcome the air pressure differential between the surface of the water that is open to atmosphere and the air pressure in the tubes.
Consider figure 2.  If you were to try to reinsert V2 into V1 again, you would have to push the water back down the riser tube that runs from the open to atmosphere reservoir to the black box.
Nice try though.

[vineet_kiran]

looked, understood, and it is a piston pump and air pressure dose act on V2.
when you bend the hose to pull on V2 you create a surface for air pressure to push it back in to
equalize the pressure.
thankyou for playing please play again.
fritznien

Mr.Fritznien,

You are a great man.

As desired by you I am playing again.  Please go through the attachment and kindly enlighten me about it.  I won't play again. (my tank is exhausted). Forgive me for sending file in excel.


Thanks,
Vineet.K.

[vineet_kiran]

I think the flaw in the reasoning is in the statement "A very interesting point here to note is that work input to the system in only energy supplied to overcome friction between tube V2 and rubber ring . . ."
This is simply not the case.  The real energy input to the system is the energy required to overcome the friction of the o-ring plus the energy to overcome the air pressure differential between the surface of the water that is open to atmosphere and the air pressure in the tubes.
Consider figure 2.  If you were to try to reinsert V2 into V1 again, you would have to push the water back down the riser tube that runs from the open to atmosphere reservoir to the black box.
Nice try though.

It is not the case.   Even when you reinsert V2 into V1 again, it pushes air (or water) from reservoir to jar without experiencing force since both ends of tube are open, making work input independent of work output.  Try it practically.

I have practically conducted this experiment.

Thanks.

[fritznien]

nothing important has changed.
mercury replaces the rubber O rings and V1 is now a box instead of a tight cylinder.
but the operation is the same.
you still pull V2 out against air pressure to create low pressure so water can be pushed up.
using brine instead of mercury would allow you to experiment more safely.
fritznien

[vineet_kiran]

you know that atmospheric pressure is equal in all directions and pressure at both ends of tube is also same. you won't pull the pipe against any air pressure which requires work

Kindly do the experiment practically.

No more arguments please.