Why is it easier to swim in sea water than in the river water ?

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

Why is it easier to swim in sea water thasn in fresh water?

(a). A body may sink in one liquid but float on another. Given examples. (b). It is easier to swi in sea water than in a river water. Why ? (c). A hollow ball has an internal diameter of 10 cm and external diameter of 12 cm. it is found that it floats on water. Find the density of the material of the ball (The volume of a sphere varies as the cube of the diameter).

Why is it easier to swim in a sea than a river ?

It is difficult to swim in sea water than in river water.

Why is a bucket of water lighter when in water than in river water?