two fences are placed inside a horizontal duct of height h and width w (inthe direction perpendicular to the plane of the figure), as shown. air of constant densityflows steadily from left to right, and the velocity upstream of the fences (station 1) isconstant across the area and equal to u1. the velocity downstream of the fences (station2) has a parabolic distribution across the duct with a maximum value um. the pressuresat stations 1 and 2 are p1 and p2, respectively, and they are constant across the duct area