Question

could you please answer the first question

2. A sediment distribution is given in the table Percent Finer CDF 0.023 0.106 0.227 0.401 0.599 0.773 0.894 0.960 0.988 (a) Find the geometric mean and standard deviation. (b) Is the sediment well sorted? (c) Determine the geometric mean and standard deviation 0.15 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 assuming that the distribution is Gaussian, Does this assumption produce good results? 3. A wide channel bed is lined with fine sand with a diameter of 0.11 mm. If the channel is filled with water with a viscosity of 1x106 m/s, what must the bed shear stress be for the sand to start moving? If flow in the channel is uniform and the channel hasa slope of 0.0002, what must the flow depth be for the sand to start

Answer 1

% Finer 2.3 8.3 12.1 17.4 19.8 17.4 12.1 6.6 1 D(mm) %Finer (CDF) 2 0.15 3 0.18 4 0.2 5 0.22 6 0.24 7 0.26 8 0.28 9 0.3 10 0.32 2.3 10.6 22.7 40.1 59.9 77.3 89.4 % Finer v/s D (mm) % Finer (CDF) v/s D (mm) 25 15 % Finer % Finer 60 98.8 12 13 d16 14 d50 15 d84 16 17 18 19 0.191 mm 0.230 mm 0.269 mm 0.050.1 015 0.2 .25 0.3 .35 0.05 0 0.15 0.2 0.25 0.3 035 D (mm) D (mm) sqrt(d34 d16) 0.227 , 天天 23 24 lơg 1.186

As seen from the Graph the sediment is well sorted

As seen from the graph the distribution is close to the guassian distribution and this assumption produce good results