What happens when a swimmer floats?

When a swimmer floats, they are able to stay on the surface of the water without sinking. This is due to two main factors: buoyancy and density.

Buoyancy is the upward force exerted by a fluid that opposes the weight of a partly or fully immersed object. In the case of a swimmer, the fluid is water. Buoyancy is caused by differences in pressure between the top and bottom of the object. The pressure is greater at the bottom of the object than at the top, which creates an upward force.

Density is the mass of an object per unit volume. The density of an object is compared to the density of the fluid in which it is immersed. If an object is less dense than the fluid, it will float. If an object is more dense than the fluid, it will sink.

In the case of a swimmer, the average density of the body is less than the density of water. This means that the swimmer is less dense than the water, and therefore will float. The amount of buoyancy a swimmer experiences is also affected by their body shape and the position of their body in the water.

When a swimmer is floating, their body is typically spread out and they are lying on their back. This position maximises the surface area of the body that is in contact with the water, which increases the amount of buoyancy they experience. Additionally, swimmers often take a deep breath before floating, which increases the volume of their body and further reduces their density.

By understanding the principles of buoyancy and density, swimmers can improve their ability to float and stay on the surface of the water.