The Formula for Linear Speed 

V(linear speed) = 

ΔSΔTΔ�Δ�

Given above is the average linear speed formula. It is the measure of the change in linear speed with respect to time over a given time period. 

∆S represents the change in distance

And ∆T represents the time taken by the body to traverse the given distance. 

V(Linear Speed) =

dsdT����

Given above is the formula of linear speed measured instantaneously. This measures the change in the distance within a fraction of a second of the motion. 

Here dS represents the instantaneous change in distance and dT represents the fraction of second taken for the change to occur. The instantaneous speed is more accurate since the period considered while finding the instantaneous linear speed is much lesser.