Physics
posted by Jenish .
How much work must be done to bring three electrons from a great distance apart to 1.0 * 10^(10)m from one another (at the corners of an equilateral triangle)?

Get it by calculating the potential energy of the configuration.
It takes ke^2/a to bring the second charge within a of the first one, and 2ke^2/a to bring in the third one within a of both of the first two. That makes a total P.E. of
3 ke^2/a, and that is the work required.
k is the Coulomb constant and e is the electron charge. 
V=k*q/r
so for the above equation, there should without square! 
1.4*10^17