Question

Why is it difficult to walk on sand?

Answer 1

Hint: We know that friction is both a boon and a bay, but it is often a useful thing, which is seen in our daily life. We also know that sand is made up of very small granules and hence cannot offer the needed resistance to our feet as compared to walking on a stationary surface.


Complete step-by-step solution:
We know from a free body diagram, that when we walk on sand, from Newton's third law of motion, it must also provide a resistive force in the opposite direction. This resistive force is commonly known as friction.
We know that friction is a resistive contact force, which acts between the surfaces of contact.The ability of friction to provide grip while walking is a great advantage to us, which prevents accidents.
Since the particles of sand are small granules, when we move our feet through then, the granules also move, thus providing a very weak resistive force against our feet. Since the friction is less, it is difficult to walk on sand.
This makes it harder for us to walk on sand as compared to a road or footpath.

Note: Keeping friction into account, the soles of the shoes or footwear have designs to provide better grip and more friction while walking. The same is also the reason why it is easy to walk on a dry floor as compared to that of a wet or oily floor. More the friction, the more comfortable it is to walk through it.