(N/A) The flow of a fluid is said to be steady if,at any given point,the velocity of each passing fluid particle remains constant in time.
This means that the velocity of any particle of the fluid remains the same while passing through a given point.
For example,let the velocity of each particle passing through point $P$ be $\overrightarrow{v_{P}}$,the velocity of each particle passing through point $Q$ be $\overrightarrow{v_{Q}}$,and the velocity of each particle passing through point $R$ be $\overrightarrow{v_{R}}$.
It is not necessary that $\overrightarrow{v_{P}} = \overrightarrow{v_{Q}} = \overrightarrow{v_{R}}$.
When a particle passes from one point to another,its velocity can change.
Steady flow is typically observed in low-velocity fluid motion. For example,the very slow motion of a water stream or slow-flowing wind.