PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential
Problem
Two point charges +5μC and −5μC are separated by 12cm in vacuum.
(i) Calculate the initial potential energy of the system.
(ii) The negative charge is slowly taken to infinity while the positive charge remains fixed. Find the work done by an external agent during this process.
(iii) Show that the change in potential energy of the system equals the negative of the work done by the electric field, and comment on the conservation of energy for the combined system and external agent.
Take 1/4πϵ0=9×109N m2 C−2.