Determine the mass flow rate through the nozzle

Question

Air at 1 MPa and 600⁰C enters a converging nozzle with a velocity of 150 m/s. Determine the mass flow rate through the nozzle for a nozzle throat area of 50 cm² when the back pressure is (i) 0.7 MPa and (ii) 0.4 MPa.

      Given:

      C_p = 1.005 kJ/kg-K

      K = 0.287 kJ/kg-K

For, $\frac{P_t}{P_o}=0.670$, M_at = 0.778 and $\frac{T_t}{T_o}=0.892$

Where, subscript t represents the properties at the throat.