A concentric tube heat exchanger for cooling lubricating oil is comprised of a thin-walled inner tube of 25 mm diameter carrying water and an outer tube of 45 mm diameter carrying the oil. The exchanger operates in counterflow with an overall heat transfer coefficient of 60W/m2K and the tabulated average properties given below. If the outlet temperature of the oil is 60oC, plot the temperature as a function of x and determine the total heat transfer, the outlet temperature of the water, and the required length.