Question

The average velocity of gas molecules is $400m{s}^{-1}$, find the rms velocity of the gas.

Answer 1

$\frac{u_{av}}{u_{rms}}=\sqrt{\frac{8RT}{\pi M}}:\sqrt{\frac{3RT}{M}}=\frac{8}{3\pi }$
$\Rightarrow u_{rms}=\sqrt{\frac{3\pi }{8}}$
$u_{av}\sqrt{\frac{3\times 3.14}{8}}\times 400=434m{s}^{-1}$