Why does a person feel lighter when swimming in pool than standing on the ground?

A person feels lighter when swimming in a pool than standing on the ground due to the buoyant force exerted by the water. Buoyant force is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In the case of swimming, the water in the pool exerts an upward force on the person's body, counteracting the downward force of gravity. This results in a net force acting upwards, causing the person to feel lighter.

The magnitude of the buoyant force is equal to the weight of the water displaced by the immersed part of the person's body. In simpler terms, the more water a person displaces, the greater the buoyant force they experience. This explains why people generally feel lighter when swimming in deeper parts of a pool compared to shallow areas.

The principle of buoyancy is also influenced by the density of the fluid. Denser fluids exert a greater buoyant force than less dense fluids. This means that a person would feel lighter when swimming in saltwater compared to freshwater, as saltwater is denser.

Overall, the feeling of lightness when swimming is a direct consequence of the buoyant force exerted by the water, which counteracts the force of gravity and reduces the net downward force on the person's body.