The Role of Surface Tension in Floating
This video explains some of the mechanics of floating for small objects (low Bond number). Surface tension and wettability effects become important for small objects. As a result, an object with a water repellent (hydrophobic) coatings will float higher in the water column than the same object with a wettable surface.
In this demonstration, the wood disks are 10 mm in length and 18 mm in diameter, floating in water. The coating is a 2-step super-hydrophobic commercial coating: Rustoleum Neverwet.
Nowadays, Archimedes’ principle can be generalized to include weight of fluid displaced by the meniscus. I hope to discuss this in a separate video. You can find the mathematical proof of the general equivalency that the weight of the fluid displaced by the meniscus is equal to the surface tension force here:
Keller, J.B., "Surface tension on partly submerged body", Physics of Fluids, vol. 10, no. 11, 1998.
https://aip.scitation.org/doi/10.1063...
This journal paper (by the Author) provides more information on the mathematical solution and the demonstration setup:
https://journals.sagepub.com/doi/pdf/...
#fluidmechanics #fluiddynamics