Air enters the compressor of a perfect-gas refrigeration cycle at 45oF, 10 psia and the turbine at

Question:

Air enters the compressor of a perfect-gas refrigeration cycle at 45oF, 10 psia and the turbine at 120oF, 30 psia. The mass flow rate of air through the cycle is 0.5 lbm/s. Determine
(a) The rate of refrigeration,
(b) The net power input and
(c) The coefficient of performance (COPR).