The ratio of R.M.S. velocity of air molecules at S. T. P. and velocity of sound in air at S.T.P. is about $(\gamma=1.41$ for air $)$

Which of the following statements is correct?

The root mean square velocity of a gas molecule of mass $m$ at a given temperature is proportional to

Given: $v_1=3 \mathrm{m} {\mathrm{s}}^{-1}, {\mathrm{v}}_2=4 \mathrm{m} {\mathrm{s}}^{-1}$ and $v_3=5 \mathrm{m} {\mathrm{s}}^{-1}$.  What is mean square velocity?

Which of the following statement is true?