Question

Hello, I do not understand what this question is asking.

Answer 1

$KE=m\cdot\frac{v^2}{2}$$\begin{gathered} KE1\cdot3=KE2 \\ 3\cdot m\cdot\frac{v_1^2}{2}=m\cdot\frac{v_2^2}{2} \\ 3v_1^2=v_2^2=(v_1+2)^2 \\ 3v_1^2=v_1^2+4v_1+4 \\ 2v_1^2-4v_1-4=0 \\ \frac{4\pm\sqrt{16-4\cdot2\cdot-4}}{4}=1\pm\frac{\sqrt{16+32}}{4}=1\pm\sqrt{3} \end{gathered}$$v_1=\sqrt{3}+1$