Pressure

Definition

*️⃣ Pressure is defined as the force applied perpendicular to the surface of an object per unit area over which that force is distributed.

In mathematical terms, it is expressed as:

$$P = \dfrac{F}{A}$$ where $P$ is the pressure,
$F$ is the force applied, and
$A$ is the area over which the force is applied

Pressure is a scalar quantity, meaning it only has magnitude and no direction.

The standard unit of pressure in the International System of Units (SI) is the pascal (Pa), which is equivalent to one newton per square meter (N/m²).

Pressure can be measured in various units depending on the context, such as scientific, industrial, or everyday use. While the pascal (Pa) is the SI unit of pressure, other units like atmospheres (atm), bar, and millimeters of mercury (mmHg) are also widely used. Each of these units can be converted to pascals, providing a standard reference for comparison and calculations.

Unit	Symbol	Equivalence in Pascals (Pa)
Pascal	Pa	1 Pa
Atmosphere	atm	101,325 Pa
Bar	bar	100,000 Pa
Millimeter of Mercury	mmHg	133.322 Pa
Torr	Torr	133.322 Pa
Pound per Square Inch	psi	6,894.76 Pa

Checking for Understanding

A rectangular block with a weight of 50 N is placed on top of a tray of sand. The base of the block has a length of 2 m and a width of 1 m. What is the pressure applied by the block?