# Bernouill's Equation Problem

Hi, I have a problem involving involving Bernoulli's equation and the emptying of a tube of liquid over time, I will outline the problem and then the question...

There is a vertical tube, which narrows into smaller tube part of the way down, it is filled with an inviscid, incompressible and irrotational fluid. The bottom/outlet of the tube is at z=0, where the cross-sectional area is represented by A0 and the fluid's speed by q1. The top of the tube is at z=1, the top level of the liquid is at h(t), where t is time, the cross-sectional area of the liquid level is A1 and the speed it is falling at is q0. The pressure is the same at both ends of the tube.

I need to find out how long it takes for the tube to empty under gravity, using Bernoulli's equation, and assuming the flow is approximately steady.

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