A rectangular channel 3 ft wide contains water 2 feet deep and flows at a velocity of 1.5 ft/sec. What is the flow rate in CFS?

To determine the flow rate in cubic feet per second (CFS) for the given rectangular channel, you can use the formula for flow rate, which is calculated as the product of the cross-sectional area and the flow velocity.

First, calculate the cross-sectional area of the channel. The width of the channel is 3 feet, and the depth of the water is 2 feet. Therefore, the area (A) can be calculated as follows:

Area (A) = width × depth

A = 3 ft × 2 ft

A = 6 square feet (sq ft)

Next, you need to multiply the cross-sectional area by the velocity of the water to find the flow rate (Q):

Flow rate (Q) = Area (A) × Velocity (V)

Q = 6 sq ft × 1.5 ft/sec

Q = 9 cubic feet per second (CFS)

This calculation shows that the flow rate is 9 CFS, making this the correct answer. Understanding this process involves recognizing the relationship between area, velocity, and flow rate, which is crucial for various applications in environmental compliance and water resource management.