People float in water because the human body weighs less than the volume of water it displaces when submerged. The buoyancy of an individual depends on his or her body type, as those with more muscle tend to sink further, while those with more body fat float more efficiently.Know More
When an object is placed into water, it is entering a cylinder of water from the surface to the bottom. It displaces some of the water in that cylinder, and the water beneath it exerts upward pressure. If the volume of water that is displaced is lighter than the object, the pressure will be insufficient to keep it afloat. If the equivalent volume of water is heavier than the object, the remaining water in the cylinder will keep it at or near the surface.
Human bodies tend to float due to stores of fat and to the volume of air stored in the lungs. However, those with very low body fat percentages may have a more difficult time managing to stay afloat. Lying horizontally can improve floating capacity, as it increases the surface area exposed to the upward pressure from the water. On the other hand, clothing can absorb water and increase in weight, possibly making the difference between floating and sinking.Learn more about Human Anatomy
The time it takes for water to freeze varies from several hours to a month, depending on the volume of water, its temperature and the temperature of the surrounding air. Water freezes when it reaches 32 degrees Fahrenheit, but the time it takes for liquid particles to reach that point differs. Large lakes and deep ponds, for instance, may take several weeks to reach a freezing point and turn to solids, while a glass filled with water may freeze overnight if left outside.Full Answer >
An ocean's salinity is affected by water and air temperature, the volume of water that flows into it, its age and the chemical composition of surrounding geological formations. Because the effect of these factors varies over the area of an ocean, different levels are found within the ocean.Full Answer >
The mouth is considered the dirtiest place in the human body. It carries the largest amount of bacteria and germs.Full Answer >
The longest bone in the human body is the femur, which is also called the thigh bone. On average, it is about 20 inches long, according to Infoplease.Full Answer >