If is the force applied to a body and is the area upon which the force is applied, then the pressure can be given as, .
The derived unit of pressure is .
Applications of Pressure
We can decrease the air pressure inside a straw by sucking out the air inside it. When this occurs the atmospheric pressure outside the liquid is more, and therefore it forces the liquid to go inside the straw and fill the vacuum or low pressure.
The area of the tip of a pin is extremely small. This enables the pin to be inserted easily into a soft board as the pressure applied is inversely proportional to the area.
The tip of a pen is kept small so that we can smoothly write on paper by applying minimum pressure.