3.1 UNDERSTANDING PRESSURE

•  Pressure is defined as force per unit area. therefore, the smaller the area, the higher the pressure.

• The SI units for pressure are Newtons per square metre (N/m²), now called Pasals (Pa) ( 1 N/m² = 1 Pa). 
• You can also use Newtons per square cm (N/cm²).

• The pressure between two solid surfaces depends on two things:

                (a) the force between the surfaces
                (b) the area of contact between the two surfaces.

• The greater the force or the smaller the area the greater the pressure.

• The pressure of a given force increases as the surface area decreases.