Question

It is easier to swim in the seawater than in the river water, because:

• A. Seawater is denser than river water.
• B. Seawater has waves.
• C. Seawater is less dense than river water.
• D. Sea water exerts less upthrust.

Answer 1

Answer: (A)

Correct option (B): Seawater is denser than river water.

We know that upthrust from water is required for swimming and the density of the fluid matters in order to gain that upthrust. The denser the fluid, more the upthrust and this is why it is easier to swim in sea water than in river water.

Seawater is denser because salt is dissolved in it.