6.11 An open-circuit wind tunnel draws in air from the atmosphere through a well-contoured nozzle. In the test section, where the flow is straight and nearly uniform, a static pressure tap is drilled into the tunnel wall. A manometer connected to the tap shows that static pressure within the tunnel is 45 mm of water below atmospheric.

Assume that the air is incompressible, and at 25 C, 100 kPa absolute.

Calculate the air speed in the wind-tunnel test section.