The three equations are: $v = u+ at$ , $s = ut$ $+$ $\dfrac{1}{2}$ . $at^2$ , $ v^2 = u^2 + 2as$ . Can I use them for both finding instantaneous and average quantities? Suppose I want to find the final instantananeous velocity then can I use the first equation or if I want to find average velocity over a time period,can I use the 1st equation? Plz explain me elaborately.