The rest mass of an electron is 9.11 $\times$ 10^-31 kg. From this information one can conclude that the rest energy of an electron is A) 8.20 $\times$ 10^-14 MeV B) 0.512 MeV C) 2.73 $\times$ 10^-22 J D) 0.00171 MeV E) 0.171 MeV

Question

Quizplus · Accepted Answer

The rest energy of an object is given by the famous equation E = mc^2, where E is the energy, m is the rest mass, and c is the speed of light. Plugging in the rest mass of an electron (9.11 x 10^-31 kg) and the speed of light (3 x 10^8 m/s), we get E = (9.11 x 10^-31 kg) x (3 x 10^8 m/s)^2 = 8.2 x 10^-14 J. To convert to MeV, we use the conversion factor 1 MeV = 1.6 x 10^-13 J, giving us E = 0.511 MeV, which is the closest answer choice.

The Rest Mass of an Electron Is 9 ×\times× 10-31 Kg ×\times×

The Rest Mass of an Electron Is 9 $\times$ 10^-31 Kg $\times$