$5-16$ A hair dryer is basically a duct of constant diameter in which a few layers of electric resistors are placed. A $5-39$ Refrigerant$-134$a al $700$ kPa and $120C$ enters an adiabatic nozzle steadily with a velocity of $20\frac{m}{s}$ and

leaves at $400$

small fan pulls the air in and forces it through the resistors where it is heated. If the density of air is $1\mathrm{.}20k\frac{g}{m^3}$ at

the inlet and $0\mathrm{.}95k\frac{g}{m^3}$ at the exit, determine the percent increase in the velocity of air as it flows through the

dryer.

FIGURE P$5-16$

Change density at the exit to $0\mathrm{.}85k\frac{g}{m^3}$