9.25 A rectangular weir is to be placed in a 6-m-wide channel to measure a nominal flow rate of 5.0 m/s while maintaining a minimal channel depth of 3.0 m. Determine a suitable rectangular weir (width L and height P) if H/P must be less than 0.4 to ensure that V/2g is negligible. What would the height / be for a 90-degree V-notch weir? If the flow rate doubles, which weir would experience the smaller change in weir head