2. A fluid with a density of , specific heat of c flows through a thin cylindrical tube with a radius of R and is cooled down by water passing around the tube with a temperature of Ta. The fluid enters into the tube with a temperature of To. The heat transfer coefficient (h) from the tube is given by the following relationship: h=A(1Bz) where z is the axial distance, A and B are constants defined for the system. The L/D ratio of the tube is extremely greater than 1. Figure 2. Heat transfer through a thin cylindrical tube a. Express the energy balance in the form of a differential equation by making appropriate assumptions (15 points). b. Solve the differential equation for finding the variation of temperature with the axial distance (20 points)