Which principle explains fluid pressure in a hydraulic system?

Pascal's principle, also known as Pascal's law, is fundamental to understanding fluid pressure in hydraulic systems. It states that when a change in pressure is applied to an enclosed fluid at rest, that pressure change is transmitted undiminished throughout the entire fluid in all directions. This principle is key to the functionality of hydraulic systems, as it allows for the multiplication of force: a small force applied to a small area can create a much larger force applied to a larger area.

For instance, in a hydraulic lift, when you push down on a small piston, the pressure you exert is transmitted throughout the hydraulic fluid, allowing a much larger piston to lift a heavy object with less effort. Because Pascal's principle specifically addresses how pressure behaves in fluids, it directly applies to the mechanics of hydraulic systems.

In contrast, the other principles mentioned are more relevant in different contexts. The principle of buoyancy pertains to floating objects in fluids, the principle of equilibrium relates to balanced forces and moments, and the principle of conservation of energy deals with energy transformations and not specifically with fluid pressure. Thus, only Pascal's principle accurately describes the core dynamics at play in hydraulic systems.