A gas with specific heat ratio of 1.4 flows along a circular pipe with a diameter, D of 35 mm. The Mach number at the entrance to the pipe is 0.2. Assume adiabatic flow conditions with friction loss coefficient given by f = 0.0025. a) Calculate the distance from the entrance of the pipe to the section at which the Mach number will be 0.6. b) For compressible, adiabatic flow, does the wall friction accelerate or decelerate the flow? Explain your answer. 95