question_answer

   (a) Distinguish thrust and pressure. (b) Why is it easier to swim in sea-water than in river water?

Answer:

           (a) Thrust The  total  perpendicular  force exerted by a body on any surface in contact with it, is called thrust. Pressure The thrust acting per unit area of a surface is called pressure.                 (b) It is easier in sea-water, because sea-water exerts more up thrust on the body than the river water.