UID Too=50C, h=100 W/mK. 6, (30 points) A long pure aluminum rod of diameter D = 20 mm is suspended in air by thin cables. The rod is cooled from an initial uniform temperature of T; = 800K to a final centerline temperature of 400K by exposing it to convective conditions characterized by transfer. What other assumptions have you made in your analysis? a. (20 points) What is the time required to cool the rod? Assume negligible radiation heat aluminum oxide (sapphire)? Why or why not? b. (5 points) Can you use the same analysis approach as in Part (a) if the rod were C(5 points) Will the required time increase, decrease, or remain the same if radiation is ambient temperature. included in the analysis? Why? Assume the surroundings temperature is equal to the