1. The problem states that the height $h$ of a fluid column is given by the formula: $$h = \frac{P}{\rho g}$$ where: - $P$ is the pressure in pascals (Pa or N/m$^2$), - $\rho$ is the density in kg/m$^3$, - $g$ is the acceleration due to gravity in m/s$^2$ (or N/kg). 2. The example calculation uses: $$P = 1000, \quad \rho = 1000, \quad g = 9.81$$ and computes: $$h = \frac{1000}{1000 \times 9.81} = \frac{1000}{9810} = 0.102\ \text{m}$$ 3. The value $g = 9.81$ m/s$^2$ is the standard acceleration due to gravity on Earth's surface. It is derived from measurements of Earth's gravitational field and represents the average gravitational acceleration experienced by objects near sea level. 4. This value comes from Newton's law of universal gravitation and Earth's mass and radius, and is widely accepted as the standard for calculations involving gravity near Earth's surface. Final answer: The gravitational acceleration $g$ used in the formula is $9.81$ m/s$^2$, which is the standard average value for Earth's gravity.