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# what is the frequency of an electromagnetic wave that has a wavelength of 72.6

Working on electeomagnetic wavelengths in class. This is so confusing....... My teacher explained it to a point, but im still not understanding. Help me please!!!

This gives me the chance to tell a teacher aka Sheldon joke.
Very very often frequency is the greek letter 'nu' which looks like this 'ν'
The day after teaching ν= c/λ  I would stand at the door and great everyone
with "What's nu"
the very few that said "C over lambda" got a bonus point in the mark book.
So remember that everyone.  What's nu is C over lambda.
{ba dum}

### 2 Answers by Expert Tutors

David L. | Chemistry TutorChemistry Tutor
5.0 5.0 (23 lesson ratings) (23)
1
Without units for the wavelength, my answer will be meaningless, but I'll put it out there anyway.  :)

Wavelength is often reported in nanometers, so I'll assume you're talking about 72.6 nm, which is in the infrared range.

The speed of light (c) is equal to the wavelength (λ) times the frequency (ν):  c = λν

So, the frequency is: ν = c / λ

Now it's plug and chug, and making sure that the units cancel properly.  Frequency should be in reciprocal seconds (s–1), which is also known as Hertz (Hz).

ν = c / λ = (2.998 x 108 m/s) / [(72.6 nm) x (1 m / 109 nm)] = 4.13 x 1015 s–1

Rick S. | Math tutor - certified to tutor at the college levelMath tutor - certified to tutor at the c...
4.7 4.7 (11 lesson ratings) (11)
1
Hello Brionna,

To find the frequency given wavelength we can use the formula: f = c/λ

f = frequency
c = speed of light = 3.0 x 108m/s
λ = greek letter lambda = wavelength in meters = 72.6 m??

I will assume that your given wavelength is in meters, if it is not you will need to convert it to meters. (For example if it is in mm then you would divide 72.6 by 1000 = .0726m)

As I said assumption is that it is in meters as you did not enter a unit,

f = (3.0 x 108m/s)/(72.6m) = 4.13 x 106

I hope this helps you, good luck.