Assessment and Qualifications Alliance (AQA) GCSE Physics Paper 2 Practice Exam

In a fluid, pressure is defined as the force exerted per unit area. This means that as the area over which a force is distributed increases, the pressure experienced by the fluid decreases, provided that the total force remains constant. The mathematical relationship can be illustrated by the formula \( P = \frac{F}{A} \), where \( P \) is pressure, \( F \) is force, and \( A \) is area.

When the area increases, if the force does not change, the pressure must decrease because the same amount of force is spread over a larger area. For example, consider standing on a solid surface versus on a bed of nails. The force from your body weight remains the same, but if you were to distribute that weight over a larger area (by lying down), the pressure on the surface decreases, demonstrating this concept effectively.

This relationship is crucial in understanding phenomena such as fluid dynamics, how pressure is applied in hydraulic systems, and the behavior of gases and liquids in various environments.