Q. The rms velocity of molecules of a gas of density $4\ kg\ m^{- 3}$ and pressure $1.2 \times 10^{5}\ {Nm}^{- 2}$ is
A) $300\ {ms}^{- 1}$
B) $900\ {ms}^{- 1}$
C) $120\ {ms}^{- 1}$
D) $600\ {ms}^{- 1}$
Explanation
(a)
$v_{rms} = \sqrt{\frac{3p}{d}}$
$\ \ \ \ \ \ \ \ \ \ = \sqrt{\frac{3 \times 1.2 \times 10^{5}}{4}} = 300\ {ms}^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.