A solid sphere (p: 800 kgfm3, cp = 4000 Jfkg-K, k = 0.4 Wlm-K} of diameter 1 cm is taken out of the refrigerator when it is at 15"C and placed in a water bath that is at 45C. a} Categorize the heat transfer based on the free or force convection method and justify your answer. b} Calculate the convective heat transfer coefficient using an appropriate practical equation