Question involving a stream of fluids

[Terilien]

When a stream falls from a fosset it thins out near the bottom. Why is that? This eems to apply to any falling fluid.

 

[russ_watters]

Velocity. It accelerates as it falls but the mass-flow rate stays the same, therefore the cross-sectional area must decrease.

 

[Terilien]

Ah I see. It seems so obvious now. so I guess if the mass flow rate changed the mass would not be conserved?