If you apply force on a body, the object will exert the same amount of force on you, which is called thrust. Thrust is a force that is perpendicular to the given area over which you applied the force.
A shark is being expelled from the sea by a strong wave; in response to the force applied by waves, the shark will exert a force on the waves, trying to move forward. The shark moves forward with the help of thrust in the sea.
The pressure is the quantity with which we can measure how much force is being exerted on a body. Pressure can be defined as the amount of thrust or force that is applied perpendicularly on a unit square meter area.
It can be represented as,
Where, \(F\) is force applied, and \(A\) is area of contact.
It can be measured in .
Force is measured in , and area is measured in .
The Pressure exerted on a body depends on two factors,
- The magnitude of the force applied perpendicularly.
- The area on which the pressure is exerted.
The S.I. unit of pressure is .
is defined as .
It can be written as,
From the above definition of pressure, pressure and area is inversely proportional, and pressure and force are directly proportional.
Let us take real-life examples. A knife has a very small and sharp edge to exert more pressure on the smaller area of the object to get the maximum effect from it.
A knife with sharp edge
From this, we can say that drilling a hole with a sharp nail is much easier when compared to the blunt one since the blunt has more area. Thus, needles, knives are designed with smaller surface areas to increase pressure at the end.
Truck with larger wheels