on relaxation. Relax to save your life!

For many years floating was fallaciously considered to be an
inborn skill. The laws of physics explain how floating occurs and how
it can be learned. Water exerts an upward pressure, "a buoyant force"

upon objects immersed in it. A swimmer will float if the buoyant force

of the water is greater than the force his body exerts upon the water.

A swimmer in the water exerts a force downward. Acting against this force
is the upward force of the water. Actual buoyancy is equal to the
difference between the upward and downward forces. Physicists have

computed that the buoyant force upon a submerged body is exactly equal

to the weight of the liquid displaced by that body. This buoyant force acts
through a point (center of buoyancy) vertically upward, and counter-
balances, in whole or in part, the weight of the body. (Fig. 1)

Most individuals can be taught to float. A person, to float, must
displace a weight of water equal to or greater than his own weight. For
example, a recruit weighing 160 pounds equals in weight 2.56 cubic feet
of water. In order for this recruit to float, he must displace a weight
of water greater than 160 pounds. If he should exhale all the air in
his lungs, he would displace about 2.51 cubic feet. This means that the
weight of the water displaced is now 156.875 pounds. However, his
actual body weight is 160. The force of his body weight downward is
greater than the buoyant force of the wate. Therefore, he will not
float. On the other hand, by inflating his lungs, he may increase his
cubic displacement in water. He should then float, since he is buoyed

up by a force greater than the force exerted by his body weight. It has

been computed that about 3 to 5 pounds of the recruit's body will float

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