Question

why is it easy walk on sand with flat shoes , than with high helled shoes

Answer 1

Reason:

In flat shoes, thrust acts upon a larger area than in high heeled shoes. Larger the area less is the pressure exerted upon the surface. Since flat shoes have more area they exert less pressure and our feet does not sink in the sand. High heeled shoes exert the same force on a less area, so the pressure is more and our feet often sinks.

Hope it helps!