Problem $2.($Use constant specific heats$)$ Air at a velocity of $300$ m$/$s enters a turbojet aircraft

engine at $32$ kPa and $-32\backslash$deg C$.$ The pressure ratio across the compressor is $12,$ and the temperature

at the turbine inlet is $1400$K$.$ Air enters the compressor at a rate of $60$ kg$/$s$.$ Find:

a$)$ The velocity of the exhaust gases

b$)$ The propulsive efficiency