Answer
$$c= 10.5\space \text{m}$$
Work Step by Step
For a circle of radius $r$, the arc length $s$ corresponding to a central angle $\theta$ (in radians) is given by $s=r\theta$.
Therefore,
$$c=(5m)\bigg(\frac{2\pi}{3}\bigg) = \frac{10\pi}{3}\space \text{m} = 10.5\space \text{m}$$
