An experimental device that produces excess heat is passively cooled. The addition of pin fins to the casing of this device is being considered to augment the rate of cooling. Consider a copper pin fin 0.25 cm in diameter that protrudes from a wall at 95C into ambient air at 25C as shown in the below figure. The heat transfer is mainly by natural convection with a coefficient equal to 10 W/m K. Calculate the heat loss, assuming that: (a) The fin is "infinitely long" (b) The fin is 2.5 cm long and the coefficient at the end is the same as around the circumference (c) How long would the fin have to be for the infinitely long solution to be correct within 5%? Wall at 95C -L. 9 to air at 25C 0.25 cm