The magnitude of root mean square velocity of oxygen atoms in an oxygen cylinder kept at zero degrees centigrade is
a) Lesser than the average velocity of the atoms
b) Greater than the average velocity
c) Equal to the average velocity
d) There is no correlation between these two quantities.

Question

The magnitude of root mean square velocity of oxygen atoms in an oxygen cylinder kept at zero degrees centigrade is
a) Lesser than the average velocity of the atoms  
b) Greater than the average velocity  
c) Equal to the average velocity  
d) There is no correlation between these two quantities.

anonymous · Answer

sqrt (3RT/M) is formula for root mean square speed...
sqrt (8RT/pi M) is the formula for average speed..

so avg speed is always less than rms speed.