A state of a thermodynamic system in which the sum of the forces, and torque, on each particle of the system is zero
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Particularly in fluid dynamics it means that fluid pressure
is defined for any point of a system spatial location LaTeX Math Inline body p(t, {\rm r})= \rm const
at any moment of time and it stays the same at all locations and not changing over time LaTeX Math Inline body \bf r
p(LaTeX Math Inline body
, {\rm r})= \rm constt
and it stays is the same at all locations and not changing over time