> At a bottleneck, the water that gets through is moving faster, but the total volume of water going through is lower. This is incorrect because the volume of

> At a bottleneck, the water that gets through is moving faster, but the total volume of water going through is lower. This is incorrect because the volume of water will be the same under I3 flow (called I-cube flow: Incompressible, Inviscid and Irrotational). Due to conservation of mass, we have mass = density x volume = density x area x speed x time Measuring the amount of volume for the same time with changing area, the only quantity that can change is the speed (recall that we have fixed the time and already assumed incompressible flow, hence density does not change). So, more area means lower speed and vice versa. But the volume always is the same under stated assumptions.