3. Consider an infinite plane with a uniform charge density of +8.5 x 10-12 C/m2. Let point A = (0, 0, 19.7 m) and point B = (0, 0, 6.4 m). Calculate the potential difference VB - VA, in V. Use ɛ0 = 8.85 x 10-12 F/m.

Fig: 1