In this 2nd video of two parts, Dr Michel van Biezen explains how to find the velocity of fluid flow in a pipe.
dV/dt = Av = constant in all circumstances (that is, even if the diameter of the pipe changes or the height of pipe varies etc.
where V is volume, A is area and v is velocity, i.e. v = dx/dt, where dx is a small displacement of fluid in a pipe.
