A mercury manometer (?=13,600 kg/m3) is connected to an air duct to measure the pressure inside. The difference in the manometer levels is 15 mm, and the atmospheric pressure is 100 kPa. Answer the following questions:
a.If the mercury level in the manometer is higher on the side open to atmospheric pressure (as compared to the side connected to the air duct), is the pressure inside the duct above or below atmospheric pressure?
b.What is the absolute pressure in the duct?