Air is compressed by a compressor from v1= 1.0 m^3/kg to v2= 0.71 m^3/kg in a reversible, isothermal process. the air temperature is maintained constant at 25 °c during this process as a result of heat transfer to the surroundings. air moves through the compressor at a rate of m 1 kg/s. a)- determine the entropy change of the air per kg of air. b)- what is the power required by the compressor? c)- what is the rate at which entropy leave the compressor?

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Atmospheric air has a temperature (dry bulb) of 80° f and a wet bulb temperature of 60° f when the barometric pressure is 14.696 psia. determine the specific humidity, grains/lb dry air. a. 11.4 c. 55.8 d. 22.5 b. 44.1