Question

Define the pascal (Pa), the S.I unit of pressure.

Answer 1

Hint: The pressure is defined as the ratio of force applied to the area of cross section . Where the force has a unit of newton and area has a unit square meter. Thus the S.I unit of pressure is Newton per square meter which is otherwise known as Pascal. This unit is very small for many of the purposes. Hence usually kilo pascal is used to define such quantities.
Formula used:
$P={\displaystyle \frac{F}{A}}$
where, P is the pressure
F is the force
A is the area

Complete answer:
$P={\displaystyle \frac{F}{A}}$
where, P is the pressure
F is the force
A is the area
Thus one pascal can be defined as the pressure applied by force of one Newton on an area of one square meter.
The pressure and stress are similar quantities. Both have the same units . That is, both of these quantities are defined as the ratio of force applied to the area of the cross section . Thus the S.I unit of stress is the same as pressure which is Newton per square meter which is otherwise known as Pascal. The standard atmospheric pressure has a value of one atmosphere. When the value of one atmosphere is converted into kilopascal it has a value about 101.325kPA. The Pascal can also be described as Newton per square meter or kilogram per meter per square second. This is also the S.I units for pressure, stress, Young’s modulus etc.

Note: The standard atmospheric pressure has a value of one atmosphere. When the value of one atmosphere is converted into kilopascal it has a value about 101.325kPA. This is also the S.I units for pressure, stress, Young’s modulus etc.are same as pressure. Thus one pascal can be defined as the pressure applied by force of one Newton on an area of one square meter.