Here are the solutions for questions 14 and 15.
14. The figure below shows a manometer connected to a gas supply. Determine the pressure of the gas. Take atmospheric pressure as 75cmHg, density of mercury 13600kg/m3.
Assumption: The pressure of the trapped air in the right arm is equal to the atmospheric pressure.
Step 1: Convert atmospheric pressure to Pascals.
Given atmospheric pressure Patm=75cmHg=0.75 mHg.
Given density of mercury ρHg=13600kg/m3.
Assume acceleration due to gravity $g =