How does cardboard float?

Cardboard is a composite material made from multiple layers of paper that have been pressed and glued together. When cardboard is placed in water, the air pockets trap tiny air bubbles, which prevents the cardboard from sinking by supporting its weight.

Here are some additional factors that contribute to the buoyancy of cardboard:

* Density: Cardboard has a low density compared to water, meaning that it displaces more water than it weighs, which allows it to float.

* Surface Tension: Surface Tension is the natural tendency of a liquid to resist an external force and contract into its smallest surface area possible. In the case of cardboard, the surface tension of water helps support the weight of the cardboard, preventing it from sinking.

* Permeability: Cardboard is permeable to water, which means it can absorb a limited amount of water before becoming saturated. This absorption helps increase the buoyancy of cardboard by adding weight to the interior while displacing an equal volume of water.

It's worth noting that while cardboard can float, it is not waterproof. Over time, cardboard will absorb water, become saturated, and sink. The rate at which cardboard sinks depends on the thickness and composition of the cardboard, the density of the water, and the presence of other factors like waves and currents.

The buoyancy of cardboard is a useful property in certain applications, such as cardboard boats and other temporary floatation devices. However, it is important to consider the limitations and potential risks of using cardboard in water for safety and practicality.