# Surface Tension of wood on water

• zorro
In summary, a uniform cube of wood that is completely wetted by water will not be affected by surface tension and will neither be buoyed up nor down. This is because the force of surface tension is tangential to the liquid surface. Cubes with edges can cause problems due to canthotaxis, which refers to the pinning of a contact line at a sharp edge. On the other hand, a perfect wetting of a sphere will result in a thin film of fluid covering it, but the sphere can still be buoyant. It is not clear what parameters govern the thickness of the film. However, perfect wetting will result in a small downward force due to surface tension, causing the sphere to be buoyed down by
zorro
Suppose a uniform cube of wood floats on the surface of water. Water wets it completely. Will it be buoyed up or down by surface tension?

The force of surface tension is tangential to the liquid surface (along the surface of liquid). So I think there is no effect on buoyancy of cube due to surface tension.

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Cubes cause problems because of the edges (canthotaxis)- let's consider a sphere instead.

Perfect wetting will result in a thin film of fluid covering the sphere, but the sphere can still be buoyant. I'm not sure what parameters govern the film thickness.

I guess perfect wetting will result in a vertical force downwards (due to surface tension). So the sphere/cube will get buoyed down by the water (though by a small amount)
What is canthotaxis by the way?

I can say that the surface tension of wood on water is a complex phenomenon that involves the interaction between the surface of the wood and the molecules of water. In this scenario, the wood cube is fully wetted by the water, meaning that the water molecules are attracted to the surface of the wood.

When a liquid wets a solid surface, the surface tension causes the liquid to spread out and form a thin layer on the solid surface. This results in a cohesive force between the liquid molecules, which creates a surface tension. However, in this case, the water molecules are already in contact with the surface of the wood, so the surface tension does not have a significant effect on the buoyancy of the cube.

The buoyancy of an object is determined by its weight and the density of the fluid it is immersed in. In this case, the wood cube is less dense than water, so it will float. The surface tension of the water may slightly affect the overall buoyancy, but it is not the main factor.

In conclusion, the surface tension of wood on water will not have a significant impact on the buoyancy of the wood cube in this scenario. The buoyancy is primarily determined by the density of the wood and the water. Further research and experiments may be needed to fully understand the role of surface tension in this situation.

## 1. What is surface tension?

Surface tension is the force that causes the molecules at the surface of a liquid to be pulled inward, creating a thin layer of tension on the surface.

## 2. How does surface tension affect wood on water?

Surface tension allows objects that are less dense than water, such as wood, to float on the surface of the water. The molecules at the surface of the water create a cohesive force that supports the object above it.

## 3. What factors affect the surface tension of wood on water?

The surface tension of wood on water is affected by the type of wood, the shape and size of the wood, and the temperature and purity of the water.

## 4. Why does a paperclip sink in water, but a paperclip with a bent edge can float?

The surface tension of water is stronger on the flat surface of the paperclip, causing it to sink. However, when the paperclip is bent, the surface tension is broken and the water can support the weight of the paperclip, allowing it to float.

## 5. Can the surface tension of wood on water be measured?

Yes, the surface tension of wood on water can be measured using a tensiometer, which measures the force required to pull an object away from the surface of the water. This can be used to determine the surface tension of the water and how it is affected by the wood.

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