Physics Form 4: Chapter 3 - Pressure

• Pressure is defined force per unit area applied in a direction perpendicular to the surface of an object
• The unit of pressure is Pascal.

• The larger the area of surface, the lower the pressure exerted on an object.
• The greater the force, the higher the pressure exerted on an object.

 Application of pressure:

When the area is small, a moderate force can create a very large pressure. This is why a sharp knife is good at cutting things: when you push the very small area of the sharp blade against something, it creates a really large pressure.

Supermodel can damage floors by walking on then in high-heeled shoes. This is because the area of the heel is small, so you can easily create enough pressure to cause a dent in the floor.

Camels have large feet to increase surface area of contact with sand. Pressure produced is small. This is why a heavy camel will not sink into sand while walking on dessert.