The determination of force exerted on a surface relies on two fundamental physical quantities: pressure and area. Pressure, defined as force per unit area, quantifies the distributed force acting perpendicularly on a surface. When pressure is known, alongside the area upon which it acts, the total force can be derived through multiplication. For example, if a fluid exerts a pressure of 10 Pascals (Newtons per square meter) on a surface with an area of 2 square meters, the resulting force is 20 Newtons.
Understanding the relationship between these three quantities is crucial in various engineering and scientific disciplines. In structural engineering, it allows the calculation of forces acting on building foundations or bridge supports due to soil pressure or wind load. In fluid mechanics, it enables the assessment of forces on submerged objects or within pressurized systems, such as hydraulic actuators. Historically, this relationship has been fundamental to the development of pressure-based technologies, from the steam engine to modern aerospace applications, providing engineers with the means to design and control force in diverse environments.