What formula is used to calculate cubic feet per second (CFS)?

The correct formula for calculating cubic feet per second (CFS) is determined by multiplying the cross-sectional area of a water body in square feet by the average velocity of the water in feet per second. This relationship fundamentally arises from the concept of flow rate, where flow (in this case, measured in cubic feet) is a product of both the area through which the water flows and how quickly the water moves through that area.

In practical terms, if you have a stream or river, the cross-sectional area represents the size of the water channel at a given point, which can vary based on width and depth. The average velocity indicates how fast the water is traveling. By combining these two factors, you can effectively determine how much water is passing through a specific section per unit time, which is critical for applications related to aquatic pest control, water management, and environmental assessments.

The other options do not accurately represent the formula for CFS. While they may relate to measurements or other flow-related calculations, they do not encapsulate the necessary components of both area and velocity that CFS requires.