a lined rectangular concrete drainage channel is 9.0 m wide and carries a discharge of 9.8 cms with a depth of 1.2 m. in order to pass under a roadway, the channel is contracted to a width of 6 m and the contraction takes place over a 5 m distance. the energy loss in the contraction is given by 1.2v2 /(2g), where v is the velocity at the upstream end of the contraction. (a) find the depth of flow at the constriction. (b) as a second design option, the channel is contracted to 4 m width, what will be the flow conditions in the channel?