Ahouse is maintained at 1 atm and 24°c, and warm air inside a house is forced to leave the house at a rate of 90 m3/h as a result of outdoor air at 5°c infiltrating into the house through the cracks. determine the rate of net energy loss of the house due to mass transfer. the gas constant of air is r = 0.287 kpa·m3/kg·k. the constant pressure specific heat of air at room temperature is cp = 1.005 kj/kg·°c.

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)