Adding 0.1 gallon to a 4-inch fill pipe raises the liquid level by how many inches?

Adding 0.1 gallon to a 4-inch fill pipe raises the liquid level by how many inches?

• A. 1.0 inch
• B. 2.0 inches
• C. 2.5 inches
• D. 1.8 inches

Answer: (D)

The height change comes from splitting the added volume by the cross‑sectional area of the pipe: height rise = volume / area. For a circular fill pipe with a 4‑inch diameter, the radius is 2 inches, so the area is πr^2 = π(2)^2 = 4π square inches, about 12.57 in^2. Convert the added volume: 0.1 gallon equals 0.1 × 231 = 23.1 cubic inches. Then the rise is 23.1 in^3 / 12.57 in^2 ≈ 1.84 inches, which rounds to 1.8 inches. So adding 0.1 gallon raises the liquid level by about 1.8 inches.

The height change comes from splitting the added volume by the cross‑sectional area of the pipe: height rise = volume / area. For a circular fill pipe with a 4‑inch diameter, the radius is 2 inches, so the area is πr^2 = π(2)^2 = 4π square inches, about 12.57 in^2. Convert the added volume: 0.1 gallon equals 0.1 × 231 = 23.1 cubic inches. Then the rise is 23.1 in^3 / 12.57 in^2 ≈ 1.84 inches, which rounds to 1.8 inches. So adding 0.1 gallon raises the liquid level by about 1.8 inches.