Question

Pressure is equal to:
A. \[\dfrac{\text{Force}}{\text{Area}}\]
B. \[\dfrac{\text{Area}}{\text{Force}}\]
C. \[\dfrac{\text{Thrust}}{\text{Area}}\]
D. \[\dfrac{\text{Area}}{\text{Time}}\]

Answer 1

Hint:Pressure is a vector quantity defined as the force applied per unit area on an object. The basic formula for pressure is Force acting perpendicularly per unit area. The area of the contact between the body and the applied force plays a significant role in the applied pressure.

Complete answer:
Simply pressure is the force exerted on any surface per unit area. But Pressure (symbol: p or P) is the force acting perpendicular to the surface of an object per unit area over which that force is acting. The perpendicular force acting on a surface is said to be thrust. Thrust is nothing but a type of reaction force described by Newton's third law.

When a system accelerates in one direction, the accelerated body will cause a force of the same magnitude but acting in the opposite direction applied to that system. The net force applied on a surface of a body in a perpendicular direction or normal direction to the surface is called thrust also. Force and thrust, is measured using the SI Unit Newton (symbol: N)
Hence the pressure could be formulated as
Pressure, \[P = \dfrac{{\text{Thrust}}}{{\text{Area}}}\]
The S.I. unit of pressure is Pascal (Pa). As S.I. unit of thrust is Newton (N) and we have Area is expressed in \[{m^2}\].So, the Unit of Pressure is\[\dfrac{N}{{{m^2}}}\,\,or\,N{m^{ - 2}}\]. It is termed as Pascal\[Pa\].

Hence the correct answer is option C.

Note:Students should get the difference between force and force acting perpendicularly to a surface. Questions may be asked to establish the relation between thrust and pressure. From the formula it is clear that for a given constant area we have pressure that is directly proportional to the thrust acting on the surface.