MCQ Detailed View

Weight is the force with which a body is pulled towards the Earth due to gravity. While a person’s mass remains constant, the distribution of weight on the ground changes depending on their posture. The pressure a person exerts depends on how much of their body weight is concentrated on a particular area of contact with the Earth.

When a man is standing, his full body weight is concentrated on the area of his feet, which is relatively small compared to other postures. This concentration means that the pressure on the ground is highest in the standing position. In contrast, when sitting, the weight is distributed over the thighs and buttocks, which increases the contact area and reduces the effective pressure. When lying down, the weight spreads across the entire back and legs, covering an even larger area, so the pressure exerted is the least.

It is important to note that the actual weight (force due to gravity) does not change; only the pressure per unit area varies with posture. This principle is a key concept in physics, particularly in mechanics and pressure. It also explains everyday phenomena such as why high heels exert more pressure on the floor than flat shoes and why mattresses or mats reduce pressure on the body by increasing contact area.

Other positions like sitting or lying down do not exert the maximum weight on the Earth because the force is spread over a larger area, reducing the pressure per unit area. Therefore, the standing position is the correct answer, as it concentrates the full body weight on the smallest contact area, exerting the most weight on the Earth.