In a home, air infiltrates from the outside through cracks around doors and windows. consider a residence where the total length of cracks is 62 m and the total internal volume is 210 m3 . due to the wind, 9.4 x 10-5 kg/s of air enters per meter of crack and exits up a chimney. assume air temperature is the same inside and out and air density is constant at 1.186 kg/m3 . if windows and doors are not opened or closed, estimate the time required for one complete air change in the building.