A U-tube manometer is used to measure the pressure difference in air (as shown in Figure 2). The height differences observed are h, = 30cm, h2 = 20cm, hz 10cm. P1 PA %3D %3D P: h2 (a) What is the pressure difference (p1 - P2) if the manometer liquid Pg is water, and the temperature is 20C? What is (p1 - P2) if the temperature is h, 50C? (b) What is the pressure difference (p, P2) if the manometer liquid Pgis mercury, and the temperature is 20C? (c) Now the working fluid (pa) is water, and the manometer fluid Pg is Bromoethylbenzene (Meriam blue). What is the pressure difference (p - P2) if the temperature is 20C? PB Figure 2: Sketch of a U-tube manometer, where h denotes the liquid height difference between different level in the two legs of the manometer.