A metal wire of length $0.5 \mathrm{~m}$ and cross-sectional area $10^{-4} \mathrm{~m}^{2}$ has breaking stress $5 \times 10^{8} \,\mathrm{Nm}^{-2}$. A block of $10 \mathrm{~kg}$ is attached at one end of the string and is rotating in a horizontal circle. The maximum linear velocity of block will be _________ $\mathrm{ms}^{-1}$.