Steam at a temperature th = 180 ∘c and p = 1.00 atm enters a heat engine at an unknown flow rate. after passing through the heat engine, it is released at a temperature tc = 100 ∘c and p = 1.00 atm . the measured power output p of the engine is 580 j/s , and the exiting steam has a heat transfer rate of hc = 2450 j/s . find the efficiency e of the engine and the molar flow rate n/t of steam through the engine. the constant pressure molar heat capacity cp for steam is 37.47 j/(mol⋅k) .

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2