A hot-water stream at 80C enters a mixing chamber with a mass flow rate of 0.5 kg/s

Question:

A hot-water stream at 80°C enters a mixing chamber with a mass flow rate of 0.5 kg/s where it is mixed with a stream of cold water at 20°C. If it is desired that the mixture leave the chamber at 42°C, determine the mass flow rate of the cold-water stream. Assume all the streams are at a pressure of 250 kPa.

T = 80°C m = 0.5 kg/s H,0 T3 = 42°C– (P = 250 kPa) T = 20°C