A student is investigating the distribution of charge in a conductor. He attaches two unopened soda cans on their sides to two foam cups with tape. He sets the soda cans with the cups onto a tabletop so that they are touching one another. Then he moves a negatively charged balloon close to the left soda can. The set up for the investigation is shown.
When the negatively charged balloon is brought close to the left soda can, electrons in the soda cans will be attracted to the positive charge on the balloon. This will cause electrons in the left soda can to move towards the right soda can, creating a buildup of negative charge on the right soda can. The movement of electrons will continue until the charges in both soda cans equalize, resulting in both soda cans having a similar negative charge.
