$25.$ A heated nozzle processing air $($cp $=1\mathrm{.}005$ kJ$/$kg$-$K$)$ steadily is receiving heat from a source at

a rate per unit mass of $7$ kJ$/$kg$.$ Incoming air conditions are $100$ kPa and $25$C$.$ The exit area

is reduced to $38\%$ of the inlet area and the temperature of the air flow is increased by $5$

degrees. Given an inlet velocity of $5$ m$/$s determine a$.)$ the change in enthalpy per unit mass

$($kJ$/$kg$),$ b$.)$ the exit velocity $($m$/$s$),$ and c$.)$ the exit pressure $($kPa$)$ of air. Neglect potential

energy changes only.