Given, $\begin{aligned}
& \mathrm{T}=3.14=\frac{2 \pi}{\omega} \
& \omega=2 \mathrm{rad} / \mathrm{s} \
& \mathrm{x}=10 \sin \left(\omega \mathrm{t}+\frac{\pi}{3}\right) \
& \mathrm{v}=\frac{\mathrm{dx}}{\mathrm{dt}}=10 \omega \cos \left(\omega \mathrm{t}+\frac{\pi}{3}\right) \
& \text { at } \mathrm{t}=0 \
& \mathrm{v}=10 \omega \cos \left(\frac{\pi}{3}\right)=10 \times 2 \times \frac{1}{2}[\mathrm{using} \omega=2 \mathrm{rad} / \mathrm{s}] \
& \mathrm{v}=10 \mathrm{~m} / \mathrm{s}
\end{aligned}$