The wastewater flow velocity in the channel immediately upstream of the screen will vary from 0.4 to 0.9 m s−1. What is the design headloss for the screens at the two extremes of flow? Assume that the friction coefficient is 0.84. A) What are the design head losses for the screens at the two extremes of flow (0.4 and 0.9 m/s) if the screen is mechanically-cleaned? B) What are the design head losses for the screens at the two extremes of flow (0.4 and 0.9 m/s) if the screen is manually-cleaned?