Question

You are a construction worker who is laying down concrete drainage pipes. Each pipe is 5 feet long and 3 inches thick, and has an outside diameter of 6.5 feet. You lay down 4 drainage pipes end to end.

At any given time, what is the volume of water that passes through the 4 drainage pipes at half capacity? Round the answer to the nearest tenth of a cubic foot.
141.3
165.8
282.6
306.6
565.2

Answer 1

Volume = 282.6 ft.²

Explanation:

Volume: V = πr²h

Step 1: The answer needs to be in cubic feet, so convert all units to feet

1. 3 ft./12 in. = 0.25 ft.

Step 2: Subtract 0.5 ft from 6.5 ft to find the actual diameter of the pipe that the water will be passing through

2. 6.5 ft. - 0.5 ft. = 6 ft.

Step 3: Plug 3 ft. (radius), 3.14 for π, and 5 ft for h

3. V = (3.14)(3 ft.)²(5 ft.)

Step 4: Solve for the V (volume)

4. V = (3.14)(9 ft.)(5 ft.) → V = (28.26)(5) → V = (28.26)(5) → V = 141.3 ft.²

Step 5: Divide 141.3 by 2, since we want half the capacity

5. 141.3 ft.²/2 = 70.65 ft.²

Step 6: Multiply 70.65 by 4 since we want the total volume of water passing through four pipes

6. 70.65 ft.² ∙ 4 = 282.6 ft.²