In a trench that is 18" wide with sewage flowing at a depth of 2', if the velocity of the sewage is 1.5 feet per second, what is the flow rate in gallons per minute?

In a trench that is 18" wide with sewage flowing at a depth of 2', if the velocity of the sewage is 1.5 feet per second, what is the flow rate in gallons per minute?

• A. 150 gal/min
• B. 500 gal/min
• C. 1,019.60 gal/min
• D. 2,019.60 gal/min

Answer: (D)

To find the flow rate of sewage in gallons per minute, the first step is to calculate the cross-sectional area of the flow and then use that to determine the flow rate. 1. **Calculate the Cross-Sectional Area**: The trench is 18 inches wide, which converts to 1.5 feet (since there are 12 inches in a foot). The depth of the sewage is 2 feet. The cross-sectional area can be calculated by multiplying the width by the depth: \[ \text{Area} = \text{Width} \times \text{Depth} = 1.5 \text{ ft} \times 2 \text{ ft} = 3 \text{ ft}^2 \] 2. **Calculate the Flow Rate in Cubic Feet per Second**: The flow rate (discharge) can be calculated by multiplying the cross-sectional area by the velocity of the sewage: \[ \text{Flow Rate (cubic feet per second)} = \text{Area} \times \text{Velocity} = 3 \text{ ft}^2 \times 1.5 \text{ ft/s} = 4.5 \text

To find the flow rate of sewage in gallons per minute, the first step is to calculate the cross-sectional area of the flow and then use that to determine the flow rate.

1. Calculate the Cross-Sectional Area: The trench is 18 inches wide, which converts to 1.5 feet (since there are 12 inches in a foot). The depth of the sewage is 2 feet. The cross-sectional area can be calculated by multiplying the width by the depth:

[

\text{Area} = \text{Width} \times \text{Depth} = 1.5 \text{ ft} \times 2 \text{ ft} = 3 \text{ ft}^2

]

2. Calculate the Flow Rate in Cubic Feet per Second: The flow rate (discharge) can be calculated by multiplying the cross-sectional area by the velocity of the sewage:

[

\text{Flow Rate (cubic feet per second)} = \text{Area} \times \text{Velocity} = 3 \text{ ft}^2 \times 1.5 \text{ ft/s} = 4.5 \text