Answer
$\omega=\frac{\pi}{20}\text{ radians per sec}$
Work Step by Step
RECALL:
$\omega=\dfrac{\theta}{t}$
Substitute the given values into the given formula above to obtain:
\begin{array}{ccc}
&\omega&=&\dfrac{\theta}{t}
\\&\omega&= &\dfrac{\frac{2\pi}{5} \text{ radians}}{8\text{ sec}}
\\&\omega&=&\frac{\pi}{20}\text{ radians per sec}\end{array}