Work to move Electron & Nuetron

[stylez03]

Homework Statement

A proton, an alpha particle, an electron, and a neutron are at rest at the corners of a square whose side length is 4.00×10^-10 m with the electron and neutron at opposite corners.

How minimum an amount of work must be done to move the particles far from each other?

Homework Equations

Use 8.85×10^-12 F/m for the permittivity of free space and 1.60×10^-19 C for the charge on an electron.

$$KE_{i} = PE_{f}$$

$$\frac {1} {2} * m_{p} * v_{i}^2 = \frac {1} {4*pi*8.85*10^{-12}} * \frac {Q^2} {R}$$

The Attempt at a Solution

I'm not exactly sure what we're trying to solve for. I was wondering if someone could clarify the problem

 

[robb_]

You do not have to consider K.E. here.
THere are oppositely charged particles near each other. HOW much energy is required to separate this configuration from the present state to a new state where al charges are inf. far away from each other.

 

[stylez03]

You do not have to consider K.E. here.
THere are oppositely charged particles near each other. HOW much energy is required to separate this configuration from the present state to a new state where al charges are inf. far away from each other.

I'm a little confused, is there an equation I can follow?

 

[stylez03]

What equation can I start from to figure out this problem?