National Fuel Gas Code Practice Test 2025 – Complete Exam Prep

To determine the pressure exerted by a column of water at its base, we can use the hydrostatic pressure formula:

Pressure (P) = Height (h) × Density (ρ) × Gravitational Acceleration (g).

In this context, the height of the water column is 100 feet. The density of fresh water is approximately 62.4 pounds per cubic foot, and the gravitational acceleration is about 32.2 feet per second squared.

First, we convert the height from feet to a pressure measurement in pounds per square inch (psi). The pressure exerted by a 1-foot column of water is approximately 0.433 psi. To find the pressure of a 100-foot column of water:

Pressure = Height × (0.433 psi/foot) = 100 feet × 0.433 psi/foot = 43.3 psi.

This rounds to approximately 43.4 psig, which is consistent with the correct answer. Understanding this calculation is crucial because it reflects how pressure in fluid systems behaves, an important consideration in the National Fuel Gas Code and various plumbing and gas applications.