Pressure is defined as the force per unit area and is typically measured in units like pascals (Pa), which are equivalent to newtons per square meter (N/m²). To derive the dimensional formula for pressure, you can start with its definition and break down the units involved:
Pressure (P) = Force (F) / Area (A)
Now, let's break down the units of force and area:
Force (F) is typically measured in newtons (N). The dimensional formula for force can be represented as [M][L][T]⁻², where:
[M] represents mass (kilograms, kg)
[L] represents length (meters, m)
[T]⁻² represents time squared (seconds squared, s⁻²)
Area (A) is typically measured in square meters (m²). The dimensional formula for area is [L]², where [L] represents length (meters, m).
Now, plug these units into the equation for pressure:
Pressure (P) = Force (F) / Area (A)
P = [M][L][T]⁻² / [L]²
To derive the dimensional formula for pressure (P), subtract the dimensions of area (L²) from the dimensions of force (MLT⁻²):
P = [M][L][T]⁻² / [L]²
P = [M][L][T]⁻²[L]⁻²
Now, simplify the expression:
P = [M][L][T]⁻²[L]⁻²
Combine the dimensions using multiplication and division rules:
P = [M][L][T]⁻²[L]⁻²
P = [M][L][L]⁻²[T]⁻²
So, the dimensional formula for pressure (P) is:
P = [M][L][L]⁻²[T]⁻²
In summary, the dimensional formula for pressure is [M][L][L]⁻²[T]⁻², where:
[M] represents mass (kg)
[L] represents length (m)
[T] represents time (s)