Conversion constant from mass to energy

[huey910]

I was told at school that if we want to calculate the rest energy of the proton, we multiply its rest mass = 938 MeVc^-2 by a factor of 1.6*10^-13. However, doesn't this convert MeV to Joules only? What about the c^2? Please explain why we can omit it in our calculations. Thank you!

 

[mathman]

c² is built into the constant you use.

 

[kptsilva]

The rest energy is 938Mev