A A2 V1 Pi - V2 process P2 Figure 4.1-1. Mass balance on a flow system. = = 4.1-2. Flow of Liquid in a Pipe and Mass Balance. A hydrocarbon liquid enters a simple flow system shown in Fig. 4.1-1 at an average velocity of 1.282 m/s, where A1 = 4.33 x 10-3 m and P1 = 902 kg/m3. The liquid is heated in the process and the exit density is 875 kg/m3. The cross-sectional area at point 2 is 5.26 x 10-3 m2. The process is steady state. a. Calculate the mass flow rate m at the entrance and exit. b. Calculate the average velocity v at 2 and the mass velocity G at 1