Having calculated the various pressure differences as a function of time, we now look at the distribution of the differences treating time as a sampling index. The Figure 3 shows the distributions calculated from the normalised histograms. It shows the distributions calculated for \(c\) = 4.5 m/s, which corredsponds to the minimum value of \(\Delta\) in Figure 4. Other values of \(c\) give rise to different distributions which in turn give rise to other values of \(\Delta\).