Afan is to be selected to ventilate a bathroom whose dimensions are 2 m 3 3 m 3 3 m. the air velocity is not to exceed 8 m/s to minimize vibration and noise. the combined efficiency of the fan–motor unit to be used can be taken to be 50 percent. if the fan is to replace the entire volume of air in 10 min, determine (a) the wattage of the fan–motor unit to be purchased, (b) the diameter of the fan casing, and (c) the pressure difference across the fan. take the air density to be 1.25 kg/m3 and disregard the effect of the kinetic energy correction factors.