A large rocket engine delivers hydrogen at 1500C and 3 MPa, k = 1.41, R = 4124

Question:

A large rocket engine delivers hydrogen at 1500°C and 3 MPa, k = 1.41, R = 4124 J/kg⋅K, to a nozzle which exits with gas pressure equal to the ambient pressure of 54 kPa. Assuming isentropic flow, if the rocket thrust is 2 MN, estimate
(a) The exit velocity; and
(b) The mass flow of hydrogen.