An adiabatic nozzle is designed to accelerate an ideal gas from nearly $0 \mathrm{~m} / \mathrm{s}, P_{1},$ and $T_{1}$ to $\mathrm{V} \mathrm{m} / \mathrm{s}$. As the efficiency of this nozzle decreases, the pressure at the nozzle exit must also be decreased to maintain the speed at $V$. Plot the change in the flow exergy as a function of the nozzle efficiency for an ideal gas (say, air).