Subject: What is the velocity of a 546 KeV beta particle?

Tables of nuclides and isotopes list kinetic energies of various decay 
products in MeV and KeV. Velocity must be calculated. However, at these speeds, 
relativistic mass is an issue. I am not interested in the kinetic energy mass 
equivalence of the beta particle, just the velocity of the particle and the 
means for directly calulating same.

That is what I really need, a formula for directly converting kinetic energy 
in MeV to velocity, for both alpha and beta particles.

Thanks for your help.
Paul

Re: What is the velocity of a 546 KeV beta particle?