Engineering & mechanics
Hydrostatic force on a vertical rectangle
Find the resultant gauge force and centre-of-pressure depth.
A clear answer. Here’s how.
For a fully submerged vertical rectangle in a constant-density liquid, resultant gauge force=ρg A hcentroid. Centre-of-pressure depth=hcentroid+h²/(12hcentroid). Top-edge depth is non-negative. Assumes still liquid, a horizontal free surface and equal ambient pressure on the reference side; atmospheric pressure, inclined panels and support reactions are not included.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Submerged rectangle width (m)
- 2
- Submerged rectangle height (m)
- 1
- Top edge depth below free surface (m)
- 0
- Liquid density (kg/m³)
- 1000
Example result
- Submerged area (m²)
- 2
- Centroid depth (m)
- 0.5
- Resultant gauge force (N)
- 9,806.65
- Centre of pressure depth (m)
- 0.666666666667