At a commercial fuel distribution center, two open-top vertical storage tanks hold the exact same grade of liquid diesel. Tank X is a wide cylinder with a base diameter. Tank Y is a tall, narrow cylinder with a base diameter. Both tanks are currently filled with diesel to an exact depth of . Which of the following statements correctly compares the hydrostatic pressure exerted by the fuel on the bottom surface of each tank?
- The pressure is identical in both tanks, because hydrostatic pressure depends only on fluid depth and density.Answer
- BThe pressure in Tank X is greater, because it contains a much larger total weight and volume of fuel.
- CThe pressure in Tank Y is greater, because the narrower base restricts the fuel and concentrates its force.
- DThe pressure cannot be compared without first calculating the total surface area of the tank walls.
Answer
The pressure is identical in both tanks, because hydrostatic pressure depends only on fluid depth and density.
Hydrostatic pressure is determined by the formula (where is fluid density, is gravity, and is vertical fluid depth). Because both tanks hold the exact same fluid at the exact same depth, the pressure at the bottom is identical. The overall width, shape, or total volume of the tank does not affect hydrostatic pressure.
Step-by-Step Solution
Key Concept
Hydrostatic pressure at a given depth depends strictly on the density of the fluid and the vertical depth itself, regardless of the container's shape, base width, or total fluid volume.