a Single clean layer of sand in a rapid-sand filter has an average grains size of 20X40 US. Mesh, porosity go 0.4, sand specific gravity of 2.65, and shape factor of 0.85. The absolute viscosity and density of water are 1.4X10^-3 Pa-s and 998 kg/m^3, respectively. For a head loss of 0.1 m, determine the filtration rate (m/d) if the depth of this layer of sane is 0.1m?