# Thread: re: hc/wavelength

1. ## re: hc/wavelength

Hi:
I'm studying quantum physics.
I'm given a wavelength and asked what the work function is in electron volts.
The answer requires that I take the equation:
⦶=hf
where h is planck's constant and f is frequency.
Next step is to change this equation to:
⦶=hc/wavelength

It is this conversion of equations that is confusing me.
How and why is this done. What is the relationship between them. And, is this anything to do with f=1/T? And, why is the universe exponentially more interesting the more you study it?

thanks

2. Originally Posted by morelemonzanybody?
Hi:
I'm studying quantum physics.
I'm given a wavelength and asked what the work function is in electron volts.
The answer requires that I take the equation:
⦶=hf
where h is planck's constant and f is frequency.
Next step is to change this equation to:
⦶=hc/wavelength

It is this conversion of equations that is confusing me.
How and why is this done. What is the relationship between them. And, is this anything to do with f=1/T? And, why is the universe exponentially more interesting the more you study it?

thanks
How: Substitute from $c = f \lambda \Rightarrow f = \frac{c}{\lambda}$

Why 1: By your own statement, you're given a wavelength as data.

Why 2: I could stalk about that for hours.

3. ## re: formulae

I understand now.
Sometimes substituting formulae from one equations into aother can be confusing to me. I guess one just has to look at what they have, and if there isn't the required information types, we then need to find which one works. Hopefully it will come with practice.
Yes. It seems there is much touché about the subject of the ever expanding universe.
Thanks