03 Feb Why does a dead body float on water?
You may have seen dead bodies floating on water in films. A human body should not float on water considering its weight. Right! Otherwise, we do not need to learn swimming to stay afloat in water. This question of why the dead body is floating might have come to your mind. Why not ask this question in your physics tuition class? So, let us answer this question today in your physics tuition class. If one does not know how to swim, he is likely to drown in water. But on the contrary, a dead body floats on water. Do you know why it is so?
According to the Archimedes’ principle, when a body is partially or fully immersed in water, it displaces water equal to its volume. A body floats in water when its weight is less than that of an equal volume of water. If its weight is same as that of an equal volume of water it will remain afloat. For example, wood or cork float on water because their densities are less than that of water. Bodies whose densities are more than that of water sink in water.
The density of the human body is less than that of the water. Therefore, when a human dead body falls in water, it floats for a few seconds in it. But when water goes into the body, its density becomes more and it sinks. But, when its body starts expanding due to further addition of water, the volume of the total body increases, resulting in again decrease in its density. In other words, the weight of the water displaced by his body becomes more than that of the body. As a result of this, it starts to float. The same theory holds good for the floating of other objects also.
We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.