Question

Why it is easier to float in sea water than in river water?

Answer 1

Because the density of sea water is more than river water

Answer 2

A man's body is lighter than water but heavier than water's head. And it happens that the total weight of the man is greater than the weight of the water displaced, and the man can sink in water. While the man has to displace more water by shifting hota arms and legs to float in water. In doing so, as the man's weight in water is equal to the man's weight, the man begins to float. The amount of sea water is greater than the river's fresh water, therefore the weight of displaced sea water quickly is equal to the weight of man. Hence floating in seawater is safer than water from the shore.