Final answer:
The rate of flow of water from a large open tank is generally constant assuming no change in the outlet area or the water level, based on the continuity equation for incompressible fluids.
Step-by-step explanation:
When water flows steadily from the large open tank, the rate of flow of water from the tank is typically constant if we assume that the cross-sectional area of the outlet and the height of the water in the tank remain unchanged. This is based on the principle of conservation of mass, which in the context of fluid mechanics, is often referred to as the continuity equation. This principle states that for an incompressible fluid, the mass flow rate must remain constant from one cross-section of a pipe to another. Therefore, if there are no external forces acting on the water such as pumps or additional inflows, and gravity is the only force in act, the flow rate would remain constant.
However, in real situations where the tank might not be refilled, as water leaves the tank, the water level will drop, which can affect the water pressure at the outlet and, thus, the flow rate might decrease over time unless compensated by other means.