An engine realising a carnot cycle lifts a mass of 500 kg, while 0.5 mj of heat is transferred at constant temperature of 700 k from a thermal reservoir to the cycle. heat is rejected from the cycle to another thermal reservoir at constant temperature of 400 k. (a) calculate the height to which the carnot engine lifts the mass. (b) calculate the height to which the mass is lifted by a real engine realising a cycle with irreversibil ities with an efficiency lower by 10% than the carnot efficiency of the engine in (a)

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.