1. The problem statement, all variables and given/known data Calculate the wavelength of a beta particle (electron) that has an energy of 4.35 × 104 eV 2. Relevant equations E = hf λ = h/mv V = W/q eV = .5mv^2 3. The attempt at a solution I can't figure out how to get electron volts into a form of energy that I'm familiar with in an equation. I tried eV = .5mv^2 , but that gave me a speed above the speed of light. I also tried using E = hf, but that also gave me a ridiculous number.