- #1

darrenhb

- 7

- 0

## Homework Statement

Pretty straight forward, I just have to show why a photon can't transfer all of its energy to an electron. I understand this in theory but I'm stuck at how to show it.

## Homework Equations

1) E

_{p}+ m

_{e}c

^{2}= E

_{p}' + E

_{e}

Where E

_{p}is the energy of the photon, E

_{p}' is the energy of the scattered photon, and the rest is obvious.

2) E = hf

3) p = p'cos([tex]\theta[/tex]) + p

_{e}cos([tex]\phi[/tex])

4) p'sin([tex]\theta[/tex]) = p

_{e}sin([tex]\phi[/tex])

p is the initial momentum of the photon, p' is the final momentum of the photon, p

_{e}is the momentum of the electron after scattering. [tex]\theta[/tex] is the angle of the scattered photon and [tex]\phi[/tex] is the angle of the scattered electron.

## The Attempt at a Solution

I figure I have to use conservation of momentum and energy to show that it's a contradiction. I was going to assume [tex]\theta[/tex] and [tex]\phi[/tex] were 0, but I'm not sure if I can do that. I've hit a roadblock, I'm not sure how to go about this. A hint in the right direction would be much appreciated!