Mechanics

A. Fluid Pressure Definition: Pressure is defined as force per unit area acting perpendicular to a surface. In fluids at rest, pressure acts equally in all directions at a given point. Explanation: Fluid pressure is the force exerted by a fluid per unit area on any surface in contact with it. For fluids at rest (hydrostatics), pressure increases with depth due to the weight of the fluid above. Pressure at any point in a stationary fluid is the same in all directions - this is known as Pascal's principle. The pressure difference between two points depends on the density of the fluid and the vertical height difference between them. Think of it as: Think of pressure like the weight of a stack of books on a table - the deeper you go in the stack (like deeper in a fluid), the more weight (pressure) you feel from the books above. Real-world application: This principle explains why dams are thicker at the bottom than at the top - they must withstand greater water pressure at greater depths. It also explains why your ears pop when diving deep in water or flying in an airplane. B.