G Saturated steam at 100 °C is condensed in a shell-and-tube heat exchanger with UA value of 2.5 kW/K. Cooling water enters at 40 °C. Determine the cooling water mass flow rate required to maintain a heat transfer rate q of 150 kW within the heat exchanger. You may assume the steam maintains 100 °C in the heat exchanger.

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