# Calculating the velocity of electron

1. Feb 4, 2010

### FloridaPhys

1. Problem: If the de Broglie wavelength of an electron is 555nm, what is its velocity?

2. Relevant equations
- λ = h/mv

3. Ok so i first did the amu-g conversion. so i got the mass of the electron is (9.13297 x 10^-28g), then i did nm-m conversion so (555 x 10^-9m) and i multiplied them and then divided by plancks constant but i got the wrong answer?

2. Feb 4, 2010

### Pengwuino

You need to show more work then this. Also, if you're using SI units, you must convert to kg, not grams.

3. Feb 4, 2010

### FloridaPhys

nvm i got the answer. its (6.6262x10^-34Js)/((9.13297x10^-25kg)/(555x10^-9m))