# Finding the period of a wave

StotleD
Let' say you have a wave plotted out on a time scale. Each increment on the line is 675 ms. There are 5 increments between each wavelength. How would I find the frequency so that I can solve for the wave's period using:

Period = 1/Hz

Homework Helper
What's the problem? Just read the scale. The period is the number of seconds it takes for one wavelength to pass by right? There are 5 increments in one wavelength and 1 increment is 675 ms, so how many seconds for one wavelength?

StotleD
The problem is I get 2.96E-4 when I multiply 675*5 then divide 1 by that. I must be doing it wrong

Homework Helper
Why divide if you need the period? Also, check your units (dimensions). Period has the dimension of time, so it's measured in seconds.

Staff Emeritus
Gold Member
StotleD : What Galileo is telling you is that you can directly read the period off the scale. You do not have to find the frequency and then invert it.

StotleD
Period = 1/Hz

StotleD
ok, thanks

geosonel
StotleD said:
Let' say you have a wave plotted out on a time scale. Each increment on the line is 675 ms. There are 5 increments between each wavelength. How would I find the frequency so that I can solve for the wave's period using:

Period = 1/Hz
Code:
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x
x   x
x       x
x           x           x
x       x
x   x
x
|<--------------------->|
5x(675 ms) = The Period (directly from graph)

Frequency = 1/(Period) = 1/(5x(675 ms))
Period = 1/(Frequency) = 1/1/(5x(675 ms)) = (5x(675 ms)) AGAIN!

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