The origin of flow work

[jacobvandijk]

@ 0:28 Looking at a pipe and being able to watch both apertures at the same time is nothing less than a miracle ;-)

[shubhamagarwal]

Nice video about flow work understanding.

[fabrizziovega]

Hello,
Why do we not consider the force that the environment is exerting on the system due to the pressure fluid element right in front of the exit? Would this not lead to work being done into the system at the exit and work being done out of the system at the inlet?
Thanks

[manishkumarmeena]

Pdv is workdone is closed system, this cannot be used to represent work done in open system