$4.(10$ points$)$ H$2$O enters a steadily operating, adiabatic turbine at $80$ bar, and $600$C and leaves it at $100$ kPa. The isentropic efficiency of this turbine is $85\%.$ The mass flow rate of water flowing through this turbine is $30$ kg$/$s$.$

P$1=200$ kPa

T$1=20$C

P$2=600$ kPa

$(4$a$).(4$p$)$ Please find the temperature, specific enthalpy, and specific entropy at the exit.

$(4$b$).(3$p$)$ Please determine the power output of this turbine.

$(4$c$).(3$p$)$ Please determine the rate of entropy production.