Afuel oil is burned with air in a boiler furnace. the combustion produces x kw of thermal energy, of which 65% is transferred as heat to boiler tubes that pass through the furnace. the combustion products pass from the furnace to a stack at 550°c. water enters the boiler tubes as a liquid at 30°c and leaves the tubes as saturated steam at 20 bar absolute. (a) calculate the rate (kg/sec) at which steam is produced. (b) estimate the volumetric flow rate of steam produced (m^3/sec) using the steam tables. (c) repeat part (b) using the ideal gas law. which result would you trust more, and why? (d) what happened to the 35% of the combustion energy that did not get transferred to the boiler tubes?