Question

explain why a person stand on a cushion and depression is much more than when he lies down on it

Answer 1

because when he stands on the cushion the area of his body's contact with the cushion is lesser as compared to when he lies on it and since area of contact is inversely proportional to pressure, depression is greater as compared to the second case ..

Answer 2

Hi,
when a person is vertically standing on a cushion the body weight is applied downward with gravitational force acting upon the body hence all the weight is applied to the cushion. Whereas when a person is lying down all the weight is transmitted equally, so all the weight is not on a specific part hence applying less weight to the cushion. Thereby, the depression is more while standing compared to when lying down.

It can be taken in a force and pressure sense, the it would be that the area of cross-section while standing is less, hence the pressure is more whereas the area of cross-section is more while lying hence pressure is less