A clear plastic pen of length 14.5 cm is rubbed with wool. The charged plastic pen is held over a small uncharged disk shaped piece of aluminium foil of diameter 0.5cm. How close you must move the pen to the foil in order to pick up the foil?
The Attempt at a Solution
Ok I thought I would let the disk be a diople and let the pen be a point charge but nothing worked. Please explain to me how I should do this question.
Thank you very much