Question

Why is it difficult to push a beach ball under water?

Answer 1

The keyword is that it "feels" more bouyant deep down, hence it is harder to keep submerged because it "feels" like it is acting against you with greater force the deeper you go.

Step-by-step explanation:

The deeper you go, the more pressure you feel. This is the core of a principle called buoyancy. ... If you push a beach ball underwater, the buoyant force pushes back with the weight of the water that the beach ball has shoved out of the way

Answer 2

As more of the ball is submerged, you increase the volume of water being displaced. The difference between the density of the water and that of the air inside the ball generates an upward force, or buoyancy, on the ball.

Once the ball is totally submerged, there should be no difference in the weight (force) required to sink the ball farther into the water, because although the pressure in the water is higher at an increased depth, its density does not change substantially. The difference in density between the water and the air in the ball remains the same. At greater depth, the ball will actually decrease in volume, and the air inside will increase in pressure, as a result of the water pressure on the flexible ball.

Step-by-step explanation: