Air enters a hair dryer at \(22^\circ {C}\) and 100 kPa with a velocity of \(3.7 \, {m/s}\), and leaves the dryer at \(83^\circ {C}\) and 100 kPa with a velocity of \(9.1 \, {m/s}\).
The exit area of the dryer is \(18.7 \, {cm}^2\), and the ambient temperature is \(22^\circ {C}\). The air is an ideal gas with gas constant \(R = 0.287 \, {kJ/kg-K}\) and isobaric specific heat \(c_p = 1.005 \, {kJ/kg-K}\).
If the change in potential energy is neglected, the second law efficiency (in %) of the dryer is .......... {(rounded off to one decimal place).}