Answer
$0.212$
Work Step by Step
$a=\frac{v^{2}-u^{2}}{2S}$
F=coefficient of friction$ \times mg=ma$
Coefficient of friction $= \frac{a}{g}$
Therefore, coefficient of kinetic friction$=\frac{v^{2}-u^{2}}{2gS}=\frac{2.5^{2}}{2\times1.5\times9.8}=0.212$