Question

Why swimming in seawater is easier than in fresh water?

Answer 1

Density of sea water is more than fresh water due to presence of various minerals and salts. Now, up-thrust is the product of density of water, volume of water displaced and the acceleration due to gravity. Thus, increase in density will increase the up-thrust. Hence, a man swimming in sea water experiences a larger up-thrust which makes it easier for him to swim.