An electron is released from rest and travels over a potential difference of 2500 v. what is its final velocity?

The electron travels through a potential difference of . This means that the loss of electrostatic potential energy of the electron is

where q is the electron charge.

For the law of conservation of energy, the electron (starting from rest and accelerated by the potential difference) acquired a kinetic energy equal to the negative of this loss of potential energy:

where  because the electron is initially at rest and so its kinetic energy is zero. Since 

where m is the electron mass, we can find the final velocity v of the electron: