2) Consider the system shown in the figure. If a change of 0.9 kPa in the pressure of air causes the brine- mercury interface in the right column to drop by 5 mm in the brine level in the right column while the pressure in the brine pipe remains constant, determine the ratio of A2/A1. Air Brine pipe sG = LI Water Area, A Arca, A Mercury SG - 13.56

Consider the tank shown (Figure 2), where the specific weight of the water is yw = 9800 N/m³ and the specific weight of molasses is ym = 1.4x104 N/m³. What is the pressure at the bottom of the tank if h1 = 3.4 m and h2 = 3.7 m. Water h2 Molasses

Hello. Our instructor solved this question and subtracted the product of water's height and specific weight from the P1 pressure, as well as oil's. He didn't factor air pressure into the equation. What is the reason why we do not use open air pressure to solve the problem?