Air enters the compressor of an ideal gas refrigeration cycle at 7°c and 35 kpa and the turbine at 37°c and 160 kpa. the mass flow rate of air through the cycle is 0.2 kg/s. assuming variable specific heats for air, determine (a) the rate of refrigeration, (b) the net power input, and (c) the coefficient of performance.

Acircular pipe of 30mm outside diameter is placed in an airstream at 30 c and latm pressure. the air moves in cross flow over the pipe at 20 m/s, while the outer surface of the pipe is maintained at 110 c. what is the drag force exerted on the pipe per unit length? what is the rate of heat transfer from the pipe per unit length?