• Support PF! Buy your school textbooks, materials and every day products Here!

?Average speed?

  • Thread starter fball558
  • Start date
  • #1
147
0
???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
 

Answers and Replies

  • #2


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.
 
Last edited:
  • #3
1
0


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
 

Related Threads for: ?Average speed?

  • Last Post
Replies
9
Views
984
  • Last Post
Replies
1
Views
20K
  • Last Post
Replies
10
Views
2K
  • Last Post
Replies
3
Views
908
  • Last Post
Replies
3
Views
730
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
15
Views
623
  • Last Post
Replies
4
Views
2K
Top