The first 25 mm section of a pin shaped fin with a diameter of 5 mm, a length of 50 mm and a heat conduction coefficient of 100 W/m-K is insulated. The remaining 25 mm part is in contact with air whose temperature is 20 °C and the heat transfer coefficient is 500 W/m2-K. The wall temperature to which the end of the insulated part of the fin is connected is given as 100 °C. The other end, whose temperature is 100 oC, has a thermal resistance of 4x10-4 m2-K/W at the interface. Calculate the temperature at the midpoint of this fin.