Air is heated as it flows subsonically through a duct. when the amount of heat transfer reaches 67 kj/kg, the flow is observed to be choked and the velocity and the static pressure are measured to be 680 m/s and 261 kpa. disregarding frictional losses, determine the velocity, static temperature, and static pressure at the duct inlet. take the properties of air to be k = 1.4, cp = 1.005 kj/kg·k, and r = 0.287 kj/kg·k.

Consider a 1.2 meter high and 2 meter wide glass window whose thickness is 6 mm and thermal conductivity is 0.78 w/m °c. the room temperature is maintained at 24 °c, while the outdoor temperature is -5 °c. the convective heat transfer coefficients on the inner and outer surfaces of the window are 10 w/m2 °c and 25 w/m2 °c respectively. (a) draw the thermal resistance network, etermine the steady rate of heat transfer t e glass window (c) determine the temperature of the inner surface of the window