Answer
$s_1=8\pi$, $s_2=\frac{16\pi}{3}$.
Work Step by Step
In half an hour the tip of the minute hand rotates an angle of $\pi$, whilst in twenty minutes the tip of the minute hand rotates an angle of $\frac{2\pi}{3}$.
The Arc Length can be counted by: $s=r\cdot \theta.$ Here $s_1=8\cdot\pi=8\pi$, $s_2=8\cdot\frac{2\pi}{3}=\frac{16\pi}{3}$.
