How fast does air with a velocity pressure of 0.20 in w.g. move through square duct?

The velocity pressure can be used to calculate the velocity of air in the duct using the formula: velocity = √(2 * pressure / air density). Assuming standard air density and converting 0.20 in w.g. to the appropriate pressure unit, the velocity of air in the duct would be approximately 903 ft/min.