We consider a vertical strut with forward speed u 15ms-1 and analyze 2d flow in a horizontal cross-sectional plane. the effect of the free surface is neglected th chord length is 5 m, and the thickness-chord length ratio is 0.10. assum u=1.35×10-6 m2 s-1 and that the flow is turbulent from the leading edge. (a) what is the drag force in nm-1 if the strut surface is smooth? (b) what is the drag force in nm1 if the strut surface has a roughness height of 150 (c) estimate the boundary-layer thickness at the trailing edge by using a formula for a smooth flat plate (d) assume that the strut surface is smooth, and plot the velocity distribution in the wake at a longitudinal distance 50mfrom the center of the strut. (e) consider two smooth struts in a tandem arrangement. the strut dimensions and the speed are as above. the longitudinal distance between the centers of the two struts is 50 m. assume the upstream strut is not influenced by the flow around the downstream strut. however, the downstream strut is influenced by the wake of the upstream strut. estimate the drag force on the downstream strut. hint: use wake solution at the center of the downstream stut to define a modified inflow velocity to the downstream strut)