My upper grade teacher in physics has lack of intelligence, and she's not in duty to help people. I would like to clear this out here.
"An electron is accelerated from rest by the electric tension 31.0 kV. Determine the mass of the electron after the acceleration."
I've based my procedure from the principles:
E = qU
E = mc^2 - m0c^2
qU = mc^2 - m0c^2
m0 = is rest mass --> m0 = 9.1093826*10^-31 kg
The Attempt at a Solution
m0c^2 = (9.1093826*10^-31)c^2 --> m0 = 8.18751672*10^-14
q31000 = mc^2 - 8.18751672*10^-14
mc^2 = 8.68413672*10^-14
m = 9.66191907*10^-31 kg
Is this correct?