Aturbine is supplied with steam at 40 bar, and 400°c which expands through the turbine in steady flow to an exit pressure of 0.2 bar. the turbine has an isentropic efficiency of 90%. if he mass flow rate is 3 kg/s, calculate the power output of the turbine. show that the process is irreversible and calculate the change of specific entropy. heat losses from the turbine are negligible. (2048 kw; 0.643 kj/kg k).

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

If a particle moves along a path such that r : (3 sin t) m and ? : 2t rad, where t is in seconds. what is the particle's acceleration in m/s in 4 seconds? a)- 16.43 b)- 16.29 c)- 15.21 d)- 13.79

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?