How many sig figs do I need to use for constants to prove that 1u = 931.5 MeV/c^2 ?

I played around getting more accurate, but never get exactly this. Do i need to use 2.9979 x 10^8 for speed?

Question

How many sig figs do I need to use for constants to prove that 1u = 931.5 MeV/c^2 ?

I played around getting more accurate, but never get exactly this. Do i need to use 2.9979 x 10^8 for speed?

samgrace · Answer

Me too, my answer is 933020219.9 eV --> 933.02 MeV with the exact speed of light used, but electron charge only at 1.6 x 10^-19, try both with increasing number of significant figures until you get that answer, is my suggestion.