Static Electricity - Mission SE2 Detailed Help

Which of the diagrams below best represents the charge distribution on a metal sphere when a negatively charged plastic tube is placed nearby?

The metal sphere has both types of excess charge with the location of each type being either concentrated on the left side, concentrated on the right side, or scattered about.

The sphere is made of metal. Metal is a conducting material; electrons are free to move about the surface of a conducting material. As such, the location of excess charge can be quickly repositioned upon the surface of a metal sphere due to the free movement of electrons.  When the charged plastic tube is brought near the metal sphere, there is a movement of electrons about the sphere's surface. This will result in a separation of charge upon the sphere - with positive charges being concentrated in one location and negative charges being concentrated in another location. The actual locations of excess charge can be predicted by thinking about the types of charge interactions (see Know the Law section).

Charge Interactions
Charged objects show a noticeable interaction with other surrounding objects. The cause of the interaction can be summarized by one of the following three statements:
  • Oppositely charged objects attract each other.
  • Like-charged objects repel each other.
  • Any charged object - whether positive or negative - will attract a neutral object.