Q9. A sample contains mixture of helium and oxygen gas. The ratio of root mean square speed of helium and oxygen in the sample, is:\\
(1) $\frac { 1 } { 32 }$\\
(2) $\frac { 2 \sqrt { 2 } } { 1 }$\\
(3) $\frac { 1 } { 2 \sqrt { 2 } }$\\
(4) $\frac { 1 } { 4 }$