Question

I need the answer for PART B

Problem 1 2 a) The figure shows three charges qi,q2, and q3, situated at corners of a rectangle of sides a 15.0 cm and b-7.0 cm For q,-4.60 μ0. q,--4.60 μC,and q3-2.00 μ0. find the electric potential at the center of the rectangle. 2.17x105 V You are correct. Computer's answer now shown above. Previous_Tries Your receipt is 160-5179 b) Continuing with the figure above, how much work is required in moving q3 to infinity while qi and q2 remain in their positions?

Answer 1

potential enegy for a two charge system is

U= kq₁q₂/R

work required will be the change in potential energy

W = U_final - U_initial

U_initial = kq₁q₂/a+ kq₂q₃/b+ kq₃q₁/(sqrt(a²+b²))

= -9*10⁹*4.6*10^-6*4.6*10^-6/0.15 - 9*10⁹*4.6*10^-6*2*10^-6/0.07 + 9*10⁹*2*10^-6*4.6*10^-6/(sqrt(0.15²+0.07²))

U_initial= -1.9522 J

U_final = kq₁q₂/a = -9*10⁹*4.6*10^-6*4.6*10^-6/0.15  

U_final= -1.2696 J

W = -1.2696 - (-1.9522)

W = 0.6826 J