A laboratory wind tunnel has a test section that is 305 mm square. Boundary-layer velocity profiles are measured at two crosssections and displacement thicknesses are evaluated from the measured profiles. At section , where the freestream speed is U1 =26m s, the displacement thickness is δ

1 =1 5 mm. At section , located downstream from section , δ

2 =2 1 mm. Calculate the change in static pressure between sections and . Express the result as a fraction of the freestream dynamic pressure at section . Assume standard atmosphere conditions.