(i) Define pressure. (ii) Why is it easy to walk on sand with flat shoes, than with high heel shoes?

(i) Pressure is defined as thrust per unit area.
(ii) With flat shoes, the weight of our body acts on large area of sand. This produces less pressure on sand so it will not sink in sand.But if we wear shoes with pointed heels, the weight of our body falls on a small area, thereby producing a large pressure on sand ,so heels will tend to sink and make walking difficult on sand.