A rectangular sedimentation tank is used to remove spherical particles with a density of 2.65 x 103 kg/m from wastewater. The fluid velocity is uniform and at laminar flow in the horizontal direction throughout the settling tank. The height of the settling tank is 3.5 m and width is 6 m. The wastewater influent flowrate is 0.2 m/s. (a) Calculate the minimum length of the tank (in meter) that is required for removing particles with a diameter 40 um at 100% efficiency (b) Using the length calculated from part (a), calculate and plot the removal efficiency for particles with a diameter ranging from 1 um to 50 um. Use a logarithmic scale for particle diameter when plotting the figure. a