Question

Differentiate between thrust and pressure.

Answer 1

Hint: Thrust and pressure are types of perpendicular forces and they have various applications in our day to day lives. Pressure is related to thrust and the area of the surface in contact. Thrust is the reason why aeroplanes or birds can fly or fishes can swim easily in water.

Complete step by step answer:
Pressure is the force acting per unit area of a surface. Its SI unit is Pascal (\[Pa\]). Pressure is always perpendicular to the surface on which it acts.
It is given by-
\[P=\dfrac{F}{A}\]
Here, \[F\] is the force acting on a body
\[A\] is the total area of the surface on which the force acts.
The total perpendicular force acting on a surface is called thrust. Its SI unit is\[N\]. Thrust is also used to overcome drag.
We can say that thrust acting per unit area is called pressure. So, we can say that,
\[\operatorname{P}=\dfrac{thrust}{A}\]

Additional Information: The frictional force applied by fluids on objects moving through them is called drag. In order to overcome drag, the objects are made to be streamlined so that they can cut through the force and move smoothly. Fluids enclosed in a container exert a force on the walls of the container as well as on the objects immersed in them and the force is equally distributed in all the directions.

Note: When the area is varied, the effect of force acting on it also varies. For example- in order to increase the thrust acting per unit area, the area is decreased, so the effect of the same force now acting on a smaller region increases significantly. That is the reason why knives are made to be sharp.