Methane enters a 5-cm ID pipe at 35C and 12 bar with an average velocity of 7.5 m/s and emerges at a point 150 m lower than the inlet at 35C and 10 bar. (a) Without doing any calculations, predict the signs (+ or -) of AE, and AE,; where A signifies (outlet - inlet). Briefly explain your reasoning. (b) Calculate AE and AE, (W), assuming that the methane behaves as an ideal gas