Increasing pressure and exerting force
Physics Narrative for 11-14
Pressure results in forces
Look at the forces acting on these surfaces. They are all linked by the pressure of the fluid inside the container and depend on the chosen area of the surface. This is a useful and interesting connection.
Notice that the direction of the force is set by the orientation of the area. The force acts on the area because of the differential bombardment by the particles inside and out (so the pressure difference).
Also note the relationship between pressure in a fluid, the area that you choose to expose to the fluid and the force acting on that surface – always at right angles to that surface.