(b) Velocity measurements in sea water are given in Table Q2. Seawater kinematic viscosity and density for typical conditions are 1.05x10 mis and 1025 kg/m respectively. Parameter Distance from the bed, z (m) Mean velocity, U (m/s) Point 1 Point 2 Point 3 1.5 1.92 3.5 2.08 5.5 2.17 Table Q2 Assuming the data represent a logarithmic layer over a hydraulically fully rough seabed with unknown sand grain size diameter, find (0) the shear velocity and bed shear stress, [12 marks) (i) the size of a sand grain (5 marks)