Speed of Electrons: 1.13*10^6 m/s

[huntingrdr]

Homework Statement

Two electrons separated by 2*10^(-10)m are released from rest. What is the speed of each electron when they are a large distance apart. (Both electrons will have the same speed.) The answer should be 1.13*10^(6)m/s.

Homework Equations

none

The Attempt at a Solution

I am not sure what formula to use. If I were given kinetic energy I think I could figure this one out, but can't with the info given. Any help on where to start?

 

[inutard]

The relevant equations are the equations for electrical potential energy and kinetic energy.
At a large distance apart, all of the potential energy stored at the start (when the e- are separated by 2*10^(-10) m) have been converted to kinetic energy.

 

[Gear300]

Some large distance probably refers to infinite. Find the initial energy of the system, which would be the electric potential energy, U. At infinite, U would mostly convert to kinetic energy, K.

If your answer exceeds the speed of light (or comes considerably close), you might want to add relativistic adjustments.

 

[inutard]

Yes. I had forgotten to mention relativistic adjustments as well. Also keep in mind that the electron has an elementary charge (this will be useful when determining the electric potential energy.)