Question

when does the body float ona water​

Answer 1

As a general rule, yes. A cadaver in the water starts to sink as soon as the air in its lungs is replaced with water. Once submerged, the body stays underwater until the bacteria in the gut and chest cavity produce enough gas—methane, hydrogen sulfide, and carbon dioxide—to float it to the surface like a balloon.

Answer 2

when the density of body is less than the density of water