A 0.5-m3 vessel contains 10 kg of refrigerant-134a at -20oC. Determine (a) the pressure, (b) the total internal energy, and (c) the mass of each phase. (a) 133 kPa, (b) 890 kJ, (c) 0.00487 m3 (C&B) Is the answer to part b a relative quantity or an absolute quantity?