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### Question regarding wavelength

Posted: Mon Oct 15, 2018 9:31 pm
When would you use λ = c/v to find wavelength and when would you use λ = hc/E to find wavelength? Are they both referring to the wavelength of a photon?

### Re: Question regarding wavelength

Posted: Mon Oct 15, 2018 9:52 pm
Which of these equations you use ultimately depends on the information you are given. However, they should both be used when dealing with the wavelengths of electromagnetic radiation. Therefore, yes, you would specifically use these equations when dealing with photons.

### Re: Question regarding wavelength

Posted: Mon Oct 15, 2018 10:41 pm
the first equation requires you to know the frequency (v) so depending if you have that or not given to you, you would use that equation. It is also used for most calculations; the second equation you mention is more specific to find the wavelength of a photon with a certain energy. In the end both should get you to the same answer so which ever is simplest to plug numbers into you should use.

### Re: Question regarding wavelength

Posted: Mon Oct 15, 2018 11:42 pm
what units are we using while working with wavelengths?

### Re: Question regarding wavelength

Posted: Tue Oct 16, 2018 12:10 am
In equations, wavelength is typically in the form of meters usually because of the other SI units given in other variables. For example, energy is given as Joules = kgm/s so the wavelength would be in meters.

### Re: Question regarding wavelength

Posted: Tue Oct 16, 2018 2:50 pm
angelagd3l wrote:what units are we using while working with wavelengths?

wavelengths are usually given in meters but usually you can switch it by a power of 10 to make nanometers, picometers, etc to make the number friendlier