question_answer

  During a period of hot weather, the atmospheric pressure on the pond in figure remains constant. Water evaporates from the pond, so that the depth h decreases.   What will be the force of the air on the surface of the pond?

Answer:

                  We know that Pressure F = P x A F  A               (pressure = constant) As water evaporates from the pond, so area will be smaller. Hence, force .will also be smaller.