4.3.2—Pressure
- Syllabus
- 9702–2028–2029
- Objective
- 4.3.2
- Level
- AS
Pressure is force per unit area acting normally on a surface
Pressure is p=F/A, where F is the normal force distributed over area A. Its SI unit is the pascal, N m⁻².
Use the force perpendicular to the surface and the actual contact area. The same force produces greater pressure over a smaller area.
A 600 N person standing on 0.030 m² exerts an average pressure of 2.0×10⁴ Pa on the floor.
Pressure is not the total force, and forces parallel to a surface do not contribute to normal pressure.
ConceptA-Level CAIE Physics AS