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

Acompressor compresses a gas, a pump compresses a liquid. for a given pressure ratio, why does it take more work to compress a gas in a compressor than a liquid in a pump? a)- for a given pressure ratio the average specific volume for a gas is much higher than the average specific volume for a liquid. b)- there is no difference. the only difference is the amount of heat generated (not work) c)- for a given pressure ratio the average volurge for a gas is much higher than the average volume for a liquid. d)-there is no difference