Ambient air at 100 kPa and 300 K is compressed isentropically in a steady-flow device to 1

Question:

Ambient air at 100 kPa and 300 K is compressed isentropically in a steady-flow device to 1 MPa. Determine
(a) The work input to the compressor,
(b) The energy of the air at the compressor exit, and
(c) The energy of compressed air after it is cooled to 300 K at 1 MPa pressure.