Consider a fluid flow with velocity field u $=($u$($x$,$ t$),$ v$($x$,$ t$),$ w$($x$,$ t$))$ in which some fluid property $($x$,$ t$)$ exists everywhere in the fluid.

For example, could be the temperature of the water. Show that the rate of change of this arbitrary property $,$ following fluid parcels, is given by

rate of change of $=$ D $/$ Dt

Model the derivation after the calculation of the acceleration of fluid parcels.