Four molecules have speed 2 km/s, 3 km/s. 4 km/s, 5 km/s The rms speed of these molecules in km/s is ............. .

Options

A. `sqrt(27/2)`
B. `sqrt(27)`
C. `2sqrt(27)`
D. `sqrt(54)`

Answer

A

Explanation

`nu_(rms)=sqrt((nu_(1)^(2)+nu_(2)^(2)+....+nu_(n)^(2))/n)=sqrt((2^(2)+3^(2)+4^(2)+5^(2))/4)=sqrt(27/2)`