Water at an average temperature of 10oC flows in a 2.5-cm-diameter tube 6 m long at a

Question:

Water at an average temperature of 10oC flows in a 2.5-cm-diameter tube 6 m long at a rate of 0.4 kg/s. The pressure drop is measured as 3 kPa. A constant heat flux is imposed, and the average wall temperature is 50oC. Estimate the exit temperature of the water.