Question

Why is it difficult to walk on dry sand?​

Answer 1

Explanation:

because there was a single bond and it is not strong

Answer 2

$\huge\underline{\underline\mathtt{Answer:-}}$

When we step on dry sand, the grains move as we try to push the ground back in order to generate the reaction force that will take u forward. The shifting sand reduces the friction making it difficult to push the ground backward. We have to step harder so that the sand underneath the foot gets compacted and firmer for better friction that will allow us to push the ground backward. Hence, it is difficult to walk on dry sand.

[$\bf\large\underline\red{Note:-}$: When sand is wet, the cohesion between the water molecules and the adhesion between water and the grains of sand makes the sand more firm. This increases the friction between the foot and wet sand and makes it easier to walk on.]