Khuzy

That's correct.

 

m_e= ~ 9.11 * 10 ^{^ -31} kg

 

E=m_ec²

 

You have energy of electron in Joules.

 

Then divide it by e = 1.602176565*10^-19

 

[math]\frac{9.11*10^{-31}kg*299792458^2}{1.602176565*10^{-19}} = 510998.928 \frac{eV}{c^2}[/math]

 

You end up with energy of electron in eV,

and then mass of electron is eV/c².

 

You need to multiply by speed of light (m/s), then divide by wavelength (m).

 

 

electron Volt is energy unit used in quantum physics. It's quantum level equivalent of Joule at macroscopic energy unit.

 

6.62607004*10^-34 J = 4.135667*10^-15 eV

 

It's E=hc/wavelength (not e=hc/wavelength),

as you can easily mix E (energy) with e (elementary electric charge).

Sorry I got a bit confused, where did you get 9.11*10^-31 kg from?

And what does m_{e mean?}

And where do electrons fit into the equation? I thought E=hc/wavelength was to find energy of a photon, so what does that have to do with electrons?

Apologies if all my questions sound childish, I am new to physics and obviously not learning it very well.

It would be right for wavelength = 1m

 

 

Because you have to divide by e, not multiply..

 

1.9864x10^-25 / 1.602176565*10^-19 = ~1.23984201714482e-006

 

 

Simply, you used multiplication instead of division..

Oh okay.

So to convert joules to electronvolts you just divide/1.602*10^-19??

Also, so far into the equation the only calculations I have made are Planck's Equation x Speed of Light, and now converted that number into electronvolts. If I am understanding correctly, you are suppose to divide 1.24e-006 by the wavelength to get the answer? After all the equation says e=hc/wavelength and I know that hc=1.24-006..

Hello, sorry if this question is out of correct forum or seems silly, I am relatively young (13) and decided to learn Physics but since I am self-teaching I am finding it hard to grasp certain concepts since I am self-teaching myself. When it came to Planck's Constant and Photons I got a bit confused. The book I am reading just put the equation e=hc/wavelength but didn't explain how to do the equation so I went online.

After going on http://www.pveducation.org/pvcdrom/2-properties-sunlight/energy-photon I entered all the numbers into my calculator, after doing 6.626x10^-34 (which is Planck's Constant) x speed of light, I got my answer to be 1.9864x10^-25. Then it said to to convert to eV (electronvolts) so I entered 1.9864x10^-25 x 1.602 x 10^-19 and the website says that the answer should be 1.24 x 10^-6 but my answer was quite different.

So now I am confused, I understand what a photon is (I think, massless and in all light rays?), but I am lost for finding its energy or what Planck's Constant is. Sorry if this question is out of place, I am just confused as I think I am taking the information of the book and that website wrong. It would be helpful if someone explained, thanks!