Two insulated charged copper spheres A and B have their centers separated by a distance of $50 ext{

Question

Two insulated charged copper spheres A and B have their centers separated by a distance of $50	ext{ cm}$. What is the mutual force of electrostatic repulsion if the charge on each is $6.5 	imes 10^{-7}	ext{ C}$? (Assume radii of A and B are negligible).

Professor PC Thomas Classes · Answer

Force $F = \frac{1}{4\pi\epsilon_0} \frac{q^2}{r^2} = \frac{9 	imes 10^9 	imes (6.5 	imes 10^{-7})^2}{(0.5)^2} = \frac{9 	imes 42.25 	imes 10^{-5}}{0.25} = 1.521 	imes 10^{-2}	ext{ N}$.