Avertical cylinder (fig. p3.227) has a 61.18-kg piston locked with a pin, trapping 10 l of r-410a at 10◦c with 90% quality inside. atmospheric pressure is 100 kpa, and the cylinder cross-sectional area is 0.006 m2. the pin is removed, allowing the piston to move and come to rest with a final temperature of 10◦c for the r-410a. find the final pressure, the work done, and the heat transfer for the r-410a.

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