Amix of 1040 steel powder is made by mixing the following powders: 220 grams of 70-80 mesh size (180-212 micron diameter) 230 grams of 170-200 mesh size (75-90 micron diameter) 270 grams of 230-270 mesh size (53-63 micron diameter) 30 grams of 400-500 mesh size (25-38 micron diameter) calculate the median particle size by weight. this 1040 steel material has a density of 7.9 g/cm3

Steel balls 12 mm in diameter are annealed by heating to 1150 k and then slowly cooled to 400 k in an air att 325 k and h -20 w/m2 k. assume the properties of the steel to be k- 40 w/m k,p 7800 kg/m3, and cp 600 j/kg k. a. determine whether lumped system method can be used to analyze this problem and if so why" b. determine the time required for the cooling process. c. determine the total amount of heat lost from each ball to the ambient air