A point charge \left( {m = 1.0\,{\rm{g}}} \right) at the end of an insulating cord of length 55 {\rm cm} is observed to be in equilibrium in a uniform horizontal electric field of 15,000\,{\rm{N/C}}, when the pendulum's position, with the charge 12 {\rm cm} above the lowest (vertical) position.
1 answer
If the field points to the right in the figure, determine the magnitude of the point charge.