Refrigerant $-134$a enters an adiabatic compressor as saturated vapor at $-20C$ and leaves at $0\mathrm{.}7$ MPa and $70C.$ The mass flow rate of the refrigerant is $1\mathrm{.}2k\frac{g}{s}.$ Determine $($a$)$ the power input to the compressor, $($b$)$ the volume flow rate of the refrigerant at the compressor inlet, and $($c$)$ the entropy generation during this process.