1. Pressure is defined as the physical quantity, it is the force applied perpendicular to the surface of objects per unit area.
2. Pressure (P) = ThrustArea .
3. The SI unit of pressure is pascal(Pa).
4. One pascal can be defined as a force of one newton applied over a surface area of a one-meter square.
5. Atmospheric air applies a pressure on the surface of the earth called atmospheric pressure.