Final answer:
Both air and ocean pressures involve the force exerted by the weight of the fluid above a surface; however, atmospheric pressure decreases with altitude due to decreasing air density, and oceanic pressure increases linearly with depth due to the constant density of water. Atmospheric pressure can crush containers when unbalanced, whereas divers must be aware of increasing water pressure with depth for safety.
Step-by-step explanation:
The pressures in the air and the ocean are similar in that they both involve the force exerted on surfaces by the weight of the fluid above. This pressure increases with depth due to the increasing mass of fluid above pushing down. A key concept here is that pressure is the force per unit area exerted by the fluid.
However, air pressure and water pressure differ in several ways. In the atmosphere, the air pressure is caused by the weight of the air in the atmosphere more or less evenly distributed above the Earth's surface. This atmospheric pressure decreases more rapidly than linearly with altitude due to the exponential decrease in air density as one ascends. On the other hand, water pressure in the ocean increases linearly with depth because the density of water is approximately constant with depth, unlike the air in our atmosphere. Moreover, because water is much denser than air, a diver experiences a greater change in pressure per unit of descent in the ocean than one would experience when moving upward in the atmosphere.
For example, atmospheric pressure is significant enough to potentially crush a metal container if it were not for the equal pressure inside the container. The pressure is a result of air molecules colliding with surfaces. Similarly, divers must be mindful of the increasing pressure as they dive deeper into the water, which can affect comfort and safety. In both cases, the pressure is related to the characteristics of the fluid, such as its density and the effect of gravity pulling it towards Earth.