An electron begins at rest, and then is accelerated by a uniform electric field of 800 n/c that extends over a distance of 4 cm. find the speed of the electron after it leaves the region of uniform electric field. the fundamental charge is 1.602 × 10−19 c and the mass of the electron is 9.109 × 10−31 kg. answer in units of m/s.

The force experienced by the electron due to the electric field is given by:


The work done by the field over a distance of d=4 cm=0.04 m is equal to the energy acquired by the electron during its motion:


Since the electron starts from rest, its initial kinetic energy is zero, so this energy acquired is equal to the final kinetic energy of the electron:

And from the formula

we can find the speed of the electron: