Answer
(a) $F = 8.0\times 10^{-17}~N$
(b) The increase in kinetic energy is $~2.4\times 10^{-19}~J$
Work Step by Step
(a) We can find the magnitude of the force exerted on the electron:
$F = E~\vert q \vert = (500.0~N/C)(1.6\times 10^{-19}~C) = 8.0\times 10^{-17}~N$
(b) We can find the work done by the electric field on the electron:
$W = F~d = (8.0\times 10^{-17}~N)(3.00\times 10^{-3}~m) = 2.4\times 10^{-19}~J$
The increase in kinetic energy is equal to the work done on the electron which is $2.4\times 10^{-19}~J$
