To study the flow of air through narrowing bronchial tubes, an experimental model was set up. A flow of a of air was supplied to one end of a horizontal pipe that has a constriction, as shown in the diagram below. The incoming flow had density of 1.3 kg/m3, pressure of 101 kPa and velocity of 4.00 m/s. The pipe diameter was 8.00 mm at the inlet and 4.45 mm at the constriction. To measure the pressure difference between the unconstricted section and the constriction, a clear U-tube was connected, as shown in the diagram. The U-tube was filled with water of density 1000 kg/m3. With the air flowing through the pipe, the height difference between the levels of fluid in the arms of the U was measured to be 10.0 mm. (a) Would the air pressure at the constriction be higher or lower than the air pressure at the inlet? Justify your answer. Calculate the pressure difference. (2.5 marks) (b) Calculate the velocity of the air at the constriction. (2.5 marks)