# Differing wavelengths of equal energy photons and electrons

1. Apr 25, 2006

### mushupork5

If a photon and an electron have the same energy how would i show that their wavelengths differ (relativistically)? Furthermore, how would I find the energy when the difference between the wavelength of the photon and electron is a factor of 4? thanks

2. Apr 25, 2006

### Hootenanny

Staff Emeritus
Welcome to PF,

You can start by showing the equations for the wavelength of a photon and an electron.

~H

3. Apr 25, 2006

### mushupork5

well the wavelength of a photon is simply h/p, for the electron i can't seem to find a formula for the wavelength

4. Apr 25, 2006

### Gokul43201

Staff Emeritus
1. mushu : The rules for this sub-forum require that you show all the effort you've made towards solving the problem before we can help you.

2. Now that you've started, go back to the question. You want to find the wavelength in terms of the energy.

3. There's a name given to the wavelength associated with a particle (or any chunk of matter). Do you remember what this name is ?

5. Apr 25, 2006

### Andrew Mason

Use the same formula. Think of the electron as a photon that has a non-zero rest mass.

AM