Determine the required pressure at the entrance of the 50-mm-diameter pipe at section 1 in Fig. 13–20, in order to produce the maximum flow of air through the pipe. Outside the pipe, the air is at...

Determine the required pressure at the entrance of the 50-mm-diameter pipe at section 1 in Fig. 13–20, in order to produce the maximum flow of air through the pipe. Outside the pipe, the air is at standard atmospheric pressure and temperature. What is the mass flow?