Why do small objects grip to wet surfaces best, but large objects grip to wet surfaces worse than a dry surface?

657 views

My question probably doesn’t even make sense so here is an example. If you pour water over a massive boulder and throw sand at it, the sand will stick to the rock better than it would without the water. For larger objects like your hand, it would make it much harder to climb that rock than without the water poured on it. Why is it the opposite?

In: Physics

3 Answers

Anonymous 0 Comments

Water really likes to bond to itself. It forms lots of intermolecular connections between various water molecules. This makes it hard to separate water.

Think of sticking two objects together with taffy. It adheres to both itself and the two objects and holds them in place. Water does the same thing, but to a lessor extent.

Water can manage to “hold on” to a very small object like a grain of sand. However, something larger will greatly overpower these bonds and then it just acts as a lubricant, with water molecules sliding over each other as your hand moves across the rock.

You are viewing 1 out of 3 answers, click here to view all answers.