A hair dryer is basically a duct of constant diameter in which a few layers of electric resistors are placed. A small fan pulls the air in and forces it through the resistors where it is heated. If the density of air is 1.20 kg/m3 at the inlet and 0.95 kg/m3 at the exit, determine the percent increase in the velocity of air as it flows through the dryer.

A motorist equips his automobile tires with a relief-type valve so that the pressure inside the tire never will exceed 240 kPa(gage). He starts a trip with a pressure of 200 kPa(gage) and a temperature of 23 degree Celcius in the tires. During the long drive, the temperature of the air in the tires reaches 83 degree Celcius. Each tire contains 0.11 kg of air. Determine (a) the mass of air escaping each tire, (b) the pressure of the tire when the temperature returns to 23 degree Celcius.  Please indicate all the conversion.