# What is the de Broglie wavelength of this electron?

1. Mar 29, 2009

### gnozahs

1. The problem statement, all variables and given/known data
What is the de Broglie wavelength of this electron?
Given is 500 eV

2. Relevant equations
KE= 1/2 mv^2
1 eV=1.602x19^-19 J

3. The attempt at a solution
I converted the 500 eV to 8.01x10^-17 via the given conversion. Now I'm stuck.

2. Mar 29, 2009

### jeffreydk

The deBroglie wavelength is given by the relation

$$\lambda = \frac{h}{p}$$

where $h$ is the plank constant and $p$ is momentum. I'm assuming the number in eV you were given is the kinetic energy of the electron--you can look up its mass to get it in terms of momentum through

$$T \text{(kinetic energy)}=\frac{p^2}{2m}$$

Can you figure how to get the wavelength of it from this?