Calculate DeltaR RMS for Air Molecule After 5s

[fball558]

?Average speed??

Homework Statement

As you have calculated, the average speed of an air molecule at room temperature is about 500 m/s. What is deltaR rms (root means squared) for an air molecule after five seconds?

answer is in mm

not even sure what mm is other than millimeters

The Attempt at a Solution

i though it would stay the same because the speed of a molecule does not depend on time though a medium does it??

i tried 500 which was given in problem (units m/s)
any help would be great
thanks

 

[txinstruments]

I'm still trying to figure this out too.
Look at pg 430 of your book.. the equation is there. I was told that we're supposed to use the mean path of nitrogen (N2) which is given on page 415.

So it's:

delta r rms = sqrt(v*d)*sqrt(t)

d= mean path of N2 (7e-8m) given on page 415.

 

[Pisfister]

then just multiply by a thousand since it is in meters and they want it in mm.. for all u phys 172 ppl out there searchin for this question