Air (γ = 1.4, r = 287 j/kg-k) enters a device (station 1) at temperature 400 k, pressure 150 kpa and velocity 150 m/s. in the device, the heat added per unit mass to the air is 2.5(105 ) j/kg, and the work done by the air (per unit mass) is 105 j/kg. questions: (a) what are the stagnation temperature and the stagnation pressure at the device entry (station 1)? {ans.: 411.2 k, 165.2 kpa} (b) what is the stagnation temperature at the device exit (station 2)? {ans.: 560.5 k} (c) can the stagnation pressure at the device exit be found with the given data? (d) determine the mach number of the flow at station 1 of the device of problem 1. is the flow compressible?