Asystem executes a power cycle while receiving 750 kj by heat transfer at a temperature of 1500 k and discharging 100 kj by heat transfer at a temperature of 500 k. another heat transfer from the system occurs at a temperature of 1000 k. determine the thermal efficiency if = 0.1 /kk.

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