Surface tension supported floating of heavy objects: Why elongated bodies float better?

• Floating of bodies heavier than the supporting liquid is discussed.
• Floating of objects possessing lateral dimensions smaller than the capillary length is treated.
• Floating these bodies is prescribed by the surface tension related effects.
• Elongated bodies are better supported by capillarity due to the increase in the perimeter of the triple line.

Floating of bodies heavier than the supporting liquid is discussed. Floating of cylindrical, ellipsoidal bodies and rectangular plates possessing lateral dimensions smaller than the capillary length is treated. It is demonstrated that more elongated bodies of a fixed volume are better supported by capillary forces, due to the increase in the perimeter of the triple line. Thus, floating of metallic needles obtains reasonable explanation.

Steel needle floating on the water surface.Figure optionsDownload high-quality image (45 K)Download as PowerPoint slide