A total amount of charge Q is non-uniformly distributed within a solid sphere of radius R. The charge per unit volume in the sphere can be written as=k/r, where k is a constant, and r is the radial distance from the center.

Compute the total energy stored in the charge distribution. In other words: how much work should you do to assemble the non-uniformly charged sphere from charges that were initially at infinity? Express your answer in terms of Q and R.