a
\({\text { As, } v_{\operatorname{ms}}=\sqrt{\frac{3 k_{B} T}{m}}} \)

\({\therefore \frac{v_{27}}{v_{127}}=\sqrt{\frac{27+273}{127+273}}=\sqrt{\frac{300}{400}}=\frac{\sqrt{3}}{2}} \)

\({\text { or } v_{127}=\frac{2}{\sqrt{3}} \times v_{27}=\frac{2}{\sqrt{3}} \times 200 \mathrm{m} \mathrm{s}^{-1}=\frac{400}{\sqrt{3}} \mathrm{m} \mathrm{s}^{-1}}\)