fluid dynamics help

Please explain and show work
4.2 The surface velocity of a river is measured at several locations $x$ and can be reasonably represented by \[ V=V_{0}+\Delta V\left(1-e^{-a x}\right) \] where $V_{0}, \Delta V$, and $a$ are constants. Find the Lagrangian description of the velocity of a fluid particle flowing along the surface if $x=$ 0 at time $t=0$.

Public Answer

KM0YZT The First Answerer