Calculating Average Speed of Molecules

[gazepdapi1]

[SOLVED] average speed

Problem:
Calculate the average speed of a molecule that strikes a small surface. How does this compare with the average speed of all molecules?

I started by using the root mean square speed as the average speed of some random molecule, for example hydrogen. So,

v(rmss) = (3RT/M)^.5 = (3*8.314*298/2.016E-3) = 1920.120594 m/s.
What I am confused about is how do I relate this with the average speed of all molecules. I would imagine that it would be a bigger value.

Any help is appreciated.
thanks

 

[gazepdapi1]

anybody?