Homework Help: Graph Frequency vs Distance

1. Sep 16, 2007

Jath

Alright, I have Physics homework where I have to graph Frequency vs Distance(I think it was distance). Well there are 3 columns, Frequency, Distance(As I said I think) than 1/Frequency. How in the world do you figure out 1/Frequency? I know that Frequency is Hz, and Hz = 1/s. So I would suppose 1/Frequency would be something like this?

Frequency Distance 1/Frequency

1 1/1/s
2 1/2/s
3 1/3/s
4 1/4/s
5 1/5/s
6 1/6/s
7 1/7/s
8 1/8/s

If so, what does s(Seconds) become?

2. Sep 16, 2007

bel

$$\frac{1}{s^{-1}} = s$$

3. Sep 16, 2007

Jath

I understand that 1/s = s, I mean my teacher gave me a gigantic formula going, Hz=1/s=1/1/s=1/s/s=s/s/s=s/s=s.... But I still don't know what the heck I am doing. :( Sorry.

Also I just found out this morning that Distance is Wavelength(cm). I still don't know how to find it though.

Last edited: Sep 17, 2007
4. Sep 17, 2007

Jath

Any ideas?

5. Sep 17, 2007

cristo

Staff Emeritus
I'm really confused as to what you're asking! You have a table with data in the three columns and you are asked to plot frequency vs. wavelength?

6. Sep 17, 2007

Jath

I'm asked to plot Wavelength v. 1/Frequency. But I have no clue on how to get the 1/Frequency Column. Right now my table looks like this.

Frequency-----Wavelength---------1/Frequency
(Hz)--------------(cm)---------------( )
1------------------60
2------------------30
3------------------20
4------------------15
5------------------12
6------------------10
7------------------8.6
8------------------7.5

7. Sep 17, 2007

cristo

Staff Emeritus
Oh, right. Well, it's just the reciprocal of the first column. So, it would look like

1/frequency
1/1=1
1/2
1/3
1/4
...

(which I now see is what you put in your first post!)

Now, the units of frequency are $$s^{-1}=\frac{1}{s}$$ so the units of 1/freq will be $$\frac{1}{1/s}$$. What does this equal?

Last edited: Sep 17, 2007
8. Sep 17, 2007

Jath

Alright thats kind of what I thought in the beginning. So mostly it would just be,

1/2
1/3
1/4

and NOT

1/1/2
1/1/3
1/1/4

Correct?

9. Sep 17, 2007

cristo

Staff Emeritus
This is correct

If you actually look at these numbers, they are the reciprocal of 1/freq, i.e. they are frequency (1/(1/2)=2). I think your teacher probably confused you. He may well have been discussing the units for 1/freq (since 1/(1/s)=s)

10. Sep 17, 2007

Jath

Alright thanks alot for your help. Definitely.

11. Sep 17, 2007

Jath

Alright so also if I am graphing, would I use .5(1/2), .33(1/3), .25(1/4) or what?

12. Sep 17, 2007

cristo

Staff Emeritus
Yes, you will plot the points at 1/2(=0.5), 1/3(=0.33), etc.

13. Sep 17, 2007

Jath

Alright thanks a lot. The only problem I had was graphing because I accidently put the changing value as the y and not the x. Now what should this become as a line when its graphed? Straight, Linear, or Squared?