Answer:
The energy required to accelerate an electron is 0.582 Mev and 0.350 Mev.
Step-by-step explanation:
We know that,
Mass of electron

Rest mass energy for electron = 0.511 Mev
(a). The energy required to accelerate an electron from 0.500c to 0.900c Mev
Using formula of rest,



(b). The energy required to accelerate an electron from 0.900c to 0.942c Mev
Using formula of rest,



Hence, The energy required to accelerate an electron is 0.582 Mev and 0.350 Mev.