Methane (CH4) flows through an insulated 15-cm-diameter pipe with f = 0.023. Entrance conditions are 600 kPa,

Question:

Methane (CH4) flows through an insulated 15-cm-diameter pipe with f = 0.023. Entrance conditions are 600 kPa, 100°C, and a mass flow of 5 kg/s. What lengths of pipe will?
(a) Choke the flow;
(b) Raise the velocity by 50%;
(c) Decrease the pressure by 50%?