22 1 BASIC CONCEPTS 0.5 do ۵ Fig. 1-17. Horseshoe section 1.4. Determine the energy and momentum coefficients for the velocity distri- bution, V = 5.75V, log(30y/k), in which Vo = flow velocity at the free surface; height of surface roughness. Assume the channel is Yo flow depth, and k == very wide and rectangular.