How does pressure change with depth in a fluid?

The correct understanding of how pressure changes with depth in a fluid is that pressure increases with depth. This phenomenon occurs due to the weight of the fluid above exerting a force on the fluid below. As you descend into a fluid, each layer of fluid adds its weight to the layers below it, leading to a higher pressure. This concept is described by the hydrostatic pressure equation, which states that the pressure at a certain depth in a fluid is equal to the pressure at the surface plus the product of the fluid's density, gravitational acceleration, and the depth.

Therefore, as depth in the fluid increases, the cumulative weight of the fluid layers above also increases, resulting in an increase in pressure. This principle applies to all fluids, whether they are liquids or gases, although the rate of change can differ based on the fluid's density. Understanding this relationship is crucial in various applications, such as diving, engineering, and the design of underwater structures, making it essential to grasp that pressure does indeed increase with depth in a fluid.