4.62 Air enters a hair dryer at a temperature of 20 °C. It is heated by blowing it with a small fan over an electrically heated coil, so that it

leaves at 50 °C through an opening with cross-sectional area 50 cm2. The heating element of the hair dryer consumes i kW and the fan consumes 100 W. What is the maximum exit velocity of the air?

Fig: 1