Potential Difference of 1200 V Gives Electron 1200 eV Kinetic Energy

[tica86]

An electron is accelerated from rest through a potential difference 1200 V. Give the electron's kinetic energy after this acceleration in electron-volts?

----I know the answer is 1200 eV but if someone could explain how to get the answer?? And how do I apply 1/2mv^2=qV

 

[gneill]

The electron-volt is a unit of energy. It's the energy obtained by an electron falling through a one volt electrical potential difference.

Remember that electrical potential is measured in Volts, and that the Volt can be broken down further in terms of units:

$$[Volt] = \frac{[Joule]}{[Coulomb]}$$

The electron has a charge in coulombs. The field bestows Volt joules per coulomb when it passes through.