Question

What is the final speed of a free electron accelerated from rest through a potential difference of -53 V? The mass of the electron is 9.11x10-31kg. You need to express the speed in km/s.

You should round your answer to an integer, indicate only the number, do not include the unit.

Answer 1

Given is:-

Potential Difference

mass of the electron  

Approach:- We have a system of only conservative forces (neglecting gravitational forces and air resistance), all of the electrical potential energy is converted into kinetic energy. Initially the electron is at rest thus its kinetic energy will be zero and final potential energy will be zero.

Solution:-

By conservation of energy

by putting all the values in above equation, we get

now entering the values, we get

or

Rounded answer = 4314