Calculate the kinetic energy of an electron with a wavelength of 1fm

1. Jan 20, 2013

richyw

1. The problem statement, all variables and given/known data

Calculate the kinetic energy of an electron with a wavelength of 1fm

2. Relevant equations

DeBroglie's relation
$$E^2=(pc)^2+\left(mc^2\right)^2$$

3. The attempt at a solution

I used debroglies relation to find momentum. plugged that in to find E, and then subtracted the rest mass to find the kinetic energy. Is this even right? Is there a better way to do it?

2. Jan 21, 2013

apelling

$$E≈pc$$