Change in Classical Velocity of an Electron

[merlinh]

Homework Statement

Copper nucleus at origin and an electron initially 2 A away from origin. Electron moved to 1A away from origin. What is the change in classical velocity of the electron?

Homework Equations

PE= (kq1q2)/r
change in PE from distance of 2A = KE

The Attempt at a Solution

change in PE from distance of 2A = KE
KE = 1/2mv^2
Change in PE =PE2-PE1=1/1-1/2= 1-1/2=1/2 J
KE=1/2m(v2-v1)^2=1/2 J
and solve for v2-v1?
I don't think I am understanding this right.

 

[the1ceman]

Homework Statement

Copper nucleus at origin and an electron initially 2 A away from origin. Electron moved to 1A away from origin. What is the change in classical velocity of the electron?

Homework Equations

PE= (kq1q2)/r
change in PE from distance of 2A = KE

The Attempt at a Solution

change in PE from distance of 2A = KE
KE = 1/2mv^2
Change in PE =PE2-PE1=1/1-1/2= 1-1/2=1/2 J
KE=1/2m(v2-v1)^2=1/2 J
and solve for v2-v1?
I don't think I am understanding this right.

I assume that the electron is orbiting the nucleus, you can use a certain equation to find the force on the electron, and you know how many protons copper nucleus has. use this to find the velocites.