# Homework Help: Calculating the speed of electrons?

1. Jan 12, 2010

### bobo343

I'm now studying particle physics again after a long break, so as a refresher I've been going through my old syllabus again.

Trouble is, most of my notes suck/are lost and my memory isn't so great when it comes to the specific equations.

So basically, what's the equation for working out the speed of an electron when you're given it's De Broglie wavelength?

Definitions of the symbols won't go a miss too ;P

2. Jan 12, 2010

### rock.freak667

the De Broglie wavelength is given by

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

h = planck's constant
m = mass
v = velocity.

3. Jan 12, 2010

### bobo343

Thankyou very much for the quick reply.