A laboratory wind tunnel has a flexible upper wall that can be adjusted to compensate for boundary-layer growth, giving zero pressure gradient along the test section. The wall boundary layers are well represented by the \(\frac{1}{7}\)-power-velocity profile. At the inlet the tunnel cross section is square, with height \(H_{1}\) and width \(W_{1}\), each equal to \(1 \mathrm{ft}\). With freestream speed \(U_{1}=90 \mathrm{ft} / \mathrm{s}\), measurements show that \(\delta_{1}=0.5\) in. and downstream \(\delta_{6}=0.65\) in. Calculate the height of the tunnel walls at (6). Determine the equivalent length of a flat plate that would produce the inlet boundary layer thickness. Estimate the streamwise distance between sections (1) and (6) in the tunnel. Assume standard air.