Arizona Plumbing Practice Exam

What is the sidewall area in square inches of a seepage pit that measures 6 feet across and 14 feet deep?

1. 28,274.56 square inches

2. 37,981.44 square inches

3. 47,123.84 square inches

4. 56,548.32 square inches

The correct answer is: 37,981.44 square inches

To determine the sidewall area of a seepage pit, which has a cylindrical shape, you can use the formula for the lateral surface area of a cylinder. The formula is: \[ \text{Lateral Surface Area} = 2 \pi r h \] where \( r \) is the radius of the cylinder and \( h \) is the height (or depth in this case). In this question, the pit measures 6 feet across, so the radius \( r \) is half of that: \[ r = \frac{6 \text{ feet}}{2} = 3 \text{ feet} \] Next, to convert feet to inches (since we need the answer in square inches), we multiply by 12: \[ r = 3 \text{ feet} \times 12 = 36 \text{ inches} \] The depth of the pit is given as 14 feet. Similarly, convert this value to inches: \[ h = 14 \text{ feet} \times 12 = 168 \text{ inches} \] Now, substitute these values into the lateral surface area formula: \[ \text{Lateral Surface Area} = 2 \pi (36 \text