Question

Describe secrets of swimming.

Answer 1

Hint: The basic principle behind swimming is the principle of buoyancy. The substance or body whose density is either equal or lesser than the density of liquid will float over the liquid while those substances whose density is more than the density of the liquid, sink down.

Complete answer:
Swimming is self-propulsion of any individual or human through the water. Usually, people do swimming for sport, exercise, recreation and in adverse conditions, to save their own life or somebody else's life.
Swimming depends on the buoyancy of the human body in water. The buoyancy or buoyant force is a force generated by the liquid in the opposite direction to the force of gravity or weight. These two forces, buoyant force and the force of gravity balance each other in liquid and the body starts floating in the liquid.
To float a body in a liquid, the buoyant force must be either equal to the force of gravity or more. It is also related to the density of the floating substance or body. If the density of the body, to swim or float in any liquid, is equal or more than the density of the liquid, then, the body will float over the liquid near the surface or above the surface, respectively.
The relative density of the human body is 0.98 in comparison to the density of water that is 1.00. Thus, the human body or the body of other animals also is naturally designed in such a way that it will float over the upper surface of the water.
In order to swim in the water, the human has to push the water in backward, which produces equal and opposite force towards the forward direction as per Newton's third law, which states every action has an equal and opposite reaction in nature.

Note:
The buoyancy is an important factor for floating and swimming. The metal has a higher density than water; it will sink if we drop any metal or coin in the water. We can create different shapes in which a large volume of air is filled like boats and ships with lesser density than water. Thus, metal can also float over water due to their empty shapes.