## Photons and Photoelectric effect

$c=\lambda v$

David Minasyan 1C
Posts: 54
Joined: Thu Jul 13, 2017 3:00 am

### Photons and Photoelectric effect

Conservation of momentum and conservation of energy imply that when a photon hits an electron on the surface of a metal with enough energy to eject it, the electron would conserve both the energy of momentum; however, if a photon has no mass - by which mv (momentum) and .5mv^2 (kinetic energy) equal 0 - where is that energy coming from? Does this have anything to do with the quantized energy of light?

Ivy Lu 1C
Posts: 54
Joined: Thu Jul 27, 2017 3:00 am

### Re: Photons and Photoelectric effect

Photons don't have mass so you wouldn't really be able to use the equation p=mv. Sorry, the first time I read that as proton.
Last edited by Ivy Lu 1C on Fri Oct 13, 2017 3:07 pm, edited 3 times in total.

Maeve Gallagher 1J
Posts: 56
Joined: Fri Sep 29, 2017 7:07 am

### Re: Photons and Photoelectric effect

yeah! Protons have mass so you can use the momentum formula p=mv, using the mass and velocity of a proton.

David Minasyan 1C
Posts: 54
Joined: Thu Jul 13, 2017 3:00 am

### Re: Photons and Photoelectric effect

Oh I thought they didn't. Okay cool