([938 MeV]/[299792 km/s])*[5.013x10^-19 kg m/s]^-1[5.013x10^-19 kg m/s]^-1

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.