Let's suppose that I have certain modes previously determined for a tube that is open/closed, how do you find the equivalent modes but for a tube that is open/open?
EDIT: I was thinking that I could use the formula of L=n x lambda/2, then isolate n and find the answer like that; however the only issue would be that I don't know the L of the new tubes

slow loris replied to slow loris's topic in Homework Help

The question states 0,00007%, and the answer says 0,7ppm.
Sorry I did a typo earlier and typed 0,0007 instead of 0,00007. Thanks for your help so much though!

Hello!
I have this question in my textbook, in which I know the answer, yet I cannot figure out how to obtain it: The air has helium 0,0007% (m/m). Convert this concentration into ppm.
The answer should be 0,7ppm.
Thank you for reading this!