4. Ethylene pipeline-E. Twenty lbm/s of ethylene gas (assumed to behave ideally) flow steadily at 60 °F in a pipeline whose internal diameter is 8 in. The pressure at upstream

location 1 is p1 downstream location 2. Why does the pressure fall, and what are the velocities of the ethylene at the two locations?60 psia, and has fallen to p2=25 psia at