Given atmospheric pressure P_atm = 75 cmHg = 0.75 mHg.

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/m$^3$.

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 $P_{atm} = 75 \text{ cmHg} = 0.75 \text{ mHg}$.
Given density of mercury $\rho_{Hg} = 13600 \text{ kg/m}^3$.
Assume acceleration due to gravity $g =