Dimensional Analysis

Dimensional Analysis

This simulation demonstrates dimensional analysis of the kinetic/potential energy equation, based on Example 2.15 from your Physics textbook.

½ m v² = m g h

[M]
Mass
[L]
Length
[T]
Time
Left Hand Side (LHS): ½ m v²

Dimensions of m: [M]

Dimensions of v: [L T⁻¹]

Dimensions of v²: [L T⁻¹]² = [L² T⁻²]

Dimensions of m v²: [M] × [L² T⁻²] = [M L² T⁻²]

The constant ½ is dimensionless

Final dimensions of LHS: [M L² T⁻²]

Right Hand Side (RHS): m g h

Dimensions of m: [M]

Dimensions of g: [L T⁻²]

Dimensions of h: [L]

Dimensions of g h: [L T⁻²] × [L] = [L² T⁻²]

Dimensions of m g h: [M] × [L² T⁻²] = [M L² T⁻²]

Final dimensions of RHS: [M L² T⁻²]

The dimensions of LHS and RHS are identical: [M L² T⁻²]
Therefore, the equation is dimensionally correct.

Physical Interpretation

This equation represents the conversion between kinetic energy (½mv²) and potential energy (mgh).

The dimensional consistency confirms that both sides of the equation represent the same physical quantity - energy.

The fundamental dimensions of energy are:

  • [M] - Mass (energy has inertia)
  • [L²] - Length squared (work is force × distance)
  • [T⁻²] - Inverse time squared (related to acceleration)

Example 2.15 Solution:

LHS dimensions: [M][L T⁻¹]² = [M L² T⁻²]

RHS dimensions: [M][L T⁻²][L] = [M L² T⁻²]

Both sides have identical dimensions, confirming the equation is dimensionally correct.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top