Question

What is Pressure ?

Answer 1

Hint:Pounds per square inch, Newtons per square metre, and Pascals are the units of pressure. Other units for describing pressure include atmosphere, bar, torr, and metres sea level.The pressure is thrust per unit area, therefore, it is proportional to thrust directly and inversely to area.

Complete answer:
The unique factor of pressure is that it is a scalar quantity, meaning that it has only magnitude and no direction. The value of pressure may be either positive or negative. At a point within a gas, pressure behaves in all directions. The pressure force at the surface of a gas works perpendicular (at right angles) to the surface.

The SI unit of pressure is the Pascal, which is a derived unit. The equation that is used to express pressure is as follows:
$P = \dfrac{F}{A}$
Where, $P$ stands for pressure. The force acting per unit area is denoted by $F$.The unit area is $A$ .

The dimensional formula of force = $[M] \times [L{T^{ - 2}}]$ = Force = $[{M^1}{L^1}{T^{ - 2}}]$ -(i)
The dimensional formula of area = $[{M^0}{L^2}{T^0}]$ -(ii)
On substituting equation (i) and (ii) in the formula we get,
Pressure (P) = $F \times {A^{ - 1}}$
$P = [{M^1}{L^1}{T^{ - 2}}] \times {[{L^2}]^{ - 1}} \\
\therefore P= {M^1}{L^{ - 1}}{T^{ - 2}}$
Therefore, the pressure is dimensionally represented as ${M^1}{L^{ - 1}}{T^{ - 2}}$ .

Note:The following are some examples of pressure that we can encounter daily:
-The vacuum cleaner's operation is an indicator of pressure. The vacuum's fan produces a low-pressure zone within the vacuum, making it possible to suck dust particles in.
-Another example of pressure is cutting with a knife. Although the knife's exposed area is minimal, the pressure is sufficient to cut the vegetables and fruits.