When two charged rods are placed a distance ddd on either side of an aluminum can, the can undergoes polarization due to electrostatic induction. The free electrons in the aluminum can redistribute themselves in response to the electric fields from the rods: electrons are attracted toward the positively charged rod and repelled by the negatively charged rod. This causes one side of the can to become negatively charged and the other side positively charged, creating induced charges on opposite sides of the can. Because the can is neutral overall, the charges induced by each rod are equal and opposite, resulting in attractive forces toward each rod. However, since the rods are placed symmetrically at equal distances, the forces balance out, and the net force on the can is zero. Therefore, the can remains stationary and does not roll toward either rod
. In summary:
- The can becomes polarized with induced positive and negative charges on opposite sides.
- Each charged rod attracts the can due to opposite charges induced on the near side.
- The forces from the two rods cancel out because they are equal in magnitude and opposite in direction.
- The can stays still and does not move.
If the can is touched by one of the rods, it can acquire a net charge and then move toward the oppositely charged rod, but without such contact and with symmetric placement, the can remains stationary
