The average velocity of gas molecules is 400 m/sec. Calculate its rms velocity at the same temperature.

Uav=8RTπM1/2                                   ….(A)Urms=3RTM1/2                                …..(B)From equations (A) and (B), we have : UrmsUav=3RTM×πM8RT1/2=3π81/2∴    Urms=Uav×3π81/2           =400ms−×3×3.14281/2           =400ms−×(1.178)1/2           =400ms−×1.085=434ms−