Dimensions of Speed

The Italian mathematician Galileo Galilei is usually credited with being the first person to calculate speed, taking into account the distance covered and the time required. Galileo specified speed as the distance by a unit of time covered. In the form of an equation that is

𝝂 = d/t

Dimensional Formula of Speed

The dimensional formula of speed is expressed as,

[ML1 T-1]


  • M = Mass

  • L = Length

  • T = Time

Derivation of Dimensions of Speed

Speed (S) = Distance × [Time]-1 ------------(1)

The dimensional formula of distance = [ML1 T0] --------(2)

And, the dimensions of time = [ML0 T1] -----------(3)

substitute equation (2) and (3) in equation (1) we get,

Speed = Distance × [Time]-1

Thus, speed is dimensionally represented as [ML1 T-1].

FAQs (Frequently Asked Questions)

1. What is the Dimension of the Speed of Light?

The dimensional function of light speed is defined as the ratio of distanced light travel in the vacuum to the time taken. Light speed takes 1/299792458 seconds for light to pass 1 meter in a vacuum. The Dimensional Light Velocity Function in Vacuum is set to be M0L1T-1.

2. Is the Dimensional Formula of Speed and Velocity the Same?

The Velocity and Speed SI unit is the same. Velocity in simple words can be expressed in a specific direction as speed. Mathematically, rpm= velocity / time.

3. What is the Dimensional Formula of Velocity?

The dimensional formula is defined as the manifestation of the physical quantity with proper dimensions, in terms of its basic unit. Velocity in simple words can be represented in a specific direction as speed. Mathematically speed= velocity / time.

Dimensional Formula of Displacement = M0L1T0.