We adopt the concepts of system and control volume.
The system is a collection of particals. The particals do not leave the
system.
The control volume is arbitrary slection of boundraies.
Particls can leave the system and boundaries can move.
These two concepts will used extensivley through the book.
The first law applied to the non accelarting system
depent on the coordinate,
discussion?can be written as
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is given by
Note that it is a very good approximation to assume that the mass is a constant for system.
The Newton law of motion to take from scriven with the integration
The pressure and the hydrostatic pressure discusion with example vintrury pump