Why do people float more easily in very salty water than water found in swimming pools?
Buoyancy is the upward force generated by an object in water. Archimedes discovered that this force in equal to the weight of the water DISPLACED by the object. Salt water is heavier than fresh water due to the high levels of minerals dissolved in it. Thus two objects of equal volume will have different buoyancy characteristics depending on the type of water they are immersed in. For example, a cubic foot of air submerged in sea water will exert and upward force of 64 pounds (equal to the weight of 1 cubic foot of seawater), whereas the same cubic foot of air immersed in freshwater will exert an upward force of 62.4 pounds (the weight of 1 cubic foot of fresh water). Therefore, the upward force generated by this cubic foot of air is 1.6 pounds greater in salt water than in fresh, resulting in a greater tendency to float. To further illustrate, assume you have a human body that displaces in volume 3 cubic feet. Assume that this body also weighs 180 pounds. In salt water, this body displ
