Why is it difficult to walk on sand?
Pressure is invesly portiponal to area so,
(1)pressure increses area decrsess or
(2)area increses pressure decreses
area covered by us is very very small so it difficult to walk on sand
area covered by us very very small so pressure exerted by us is very large according to fourmula !!!!!!
here area dcreses and pressure increses
3rd Law: action/reactionWhen you walk, the reaction force from the substrate (floor, sand, etc.) is what pushes you forward. On sand, the reaction force is divided over many, many small particles, and is scattered into a myriad of directions. This scattering does not leave a lot of reaction force pointed toward your foot, so a lot of your effort is scattered -- that is, lost.