The discharge from an old sewer 400 m long when flowing full has been measured as 40 l/s. The pipe diameter is 200 mm and has an estimated surface roughness of 0.6 mm. Taking the kinematic viscosity as 1.0 mm/s, calculate the head loss in the pipe. (the non dimensional friction factor -0.02; g is taken as 9.81 m/s²)​

Afan that can provide air speeds up to 60 m/s is to be used in a low-speed wind tunnel with atmospheric air at 35 c. if one wishes to use the wind tunnel to study flat-plate boundary layer behavior up to reynolds numbes of re 10, what is the minimum plate length that should be used? at what distance from the leading edge would transition occur if the critical reynolds nurnber were rer,e = 5 × 105?