Question is if 2 positive charges (+Q) are affixed so that they can only move along the x axis, one charge at x = +d and the other at x = -d. When a third charge (+q) of mass (m) is displaced from the origin by a small distance (s) and then is released from rest show that the the charge (+q) will be in simple harmonic motion.

F= kq1q2/r^2 F= ma F = -kx let z = spring constant ie F=-zx

z= (2pif)^2 * m

Having a little trouble on how to put this together.