\({K_{{{\max }_1}}} = \frac{1}{2}mv_1^2 = 3h{v_0} - h{v_0} = 2h{v_0}\,\,\,\,\,\,\,.....(1)\)
\({K_{{{\max }_2}}} = \frac{1}{2}mv_2^2 = 9h{v_0} - h{v_0} = 8h{v_0}\,\,.....(2)\)
\((1)/(2)\,\) \( \Rightarrow \,\frac{{v_1^2}}{{v_2^2}} = \frac{{2h{v_0}}}{{8h{v_0}}} = \frac{1}{4} \Rightarrow \frac{{{v_1}}}{{{v_2}}} = \frac{1}{2}\)
$\left\lfloor{m}_{e}=\text { mass of electron }=9 \times 10^{-31} \,{kg}\right.$
${h}=\text { Planck constant }=6.6 \times 10^{-34} {Js}$
$\left.{k}_{{B}}=\text { Boltzmann constant }=1.38 \times 10^{-23}\, {JK}^{-1}\right]$