Problem 2A: Water is transported between two buildings through two isothermal circular pipes as shown in the figure below. One pipe is carrying hot water at an average temperature of 80C, while the other pipe is carrying cold water at an average temperature of 20C. Pipes are parallel to each other and buried under the soil (k-0.3 W/m-K). The diameters of hot and cold water pipes are 10cm and 12cm, respectively. The length of each pipe is 20m, while the distance between the pipes is 0.5 m. Consider the soil as an infinite medium. (a) List the assumptions and select a method of solving this problem [2 points]. (b) Determine the heat transfer rate between the pipes [5 points]. (c) Calculate the temperature drop in the hot water pipe if the hot water velocity is 0.5 m/s [3 points]. Building 1 Soil Hot water pipe Cold water pipe Building 2