why is the pressure more on ground when a person is walking than when he is standing ?

The pressure on the ground is typically greater when a person is walking compared to when they are standing still. This is due to a combination of factors such as changes in weight distribution and the mechanics of walking.

When a person is walking, their weight shifts from one foot to the other with each step. As a result, the force applied by the foot on the ground increases, leading to a higher pressure. In contrast, when a person is standing still, the weight is distributed evenly between both feet, resulting in less pressure on each foot and the ground.

Additionally, the walking motion introduces dynamic forces. When a person takes a step, they momentarily push off with their toes, creating a brief increase in pressure on the ground as they propel themselves forward. This cyclic increase in pressure during walking also contributes to the overall higher pressure compared to standing.

To calculate the exact increase in pressure, you can consider the basic principles of physics. The pressure exerted by an object is equal to the force applied to a surface divided by the area over which the force is distributed. When a person stands still, their weight is distributed over both feet, resulting in a larger surface area and lower pressure. However, when they walk, the weight is concentrated on each foot, decreasing the surface area and increasing the pressure.

By measuring the person's weight and the area of contact between their foot and the ground, you can calculate the pressure using the equation P = F/A, where P is pressure, F is force, and A is the contact area.

It's important to note that the pressure experienced during walking varies between individuals due to factors such as body weight, gait pattern, footwear, and surface conditions.