7.2 ELECTRIC FORCE BC Science 9: p
Force A force is a push or a pull. – Eg. Shooting a basketball or pulling a wagon. Forces that are directly applied (ie. through direct contact) are known as contact forces.
Electric Force Electric force can push or pull both without touching the object. – It is also known as an action-at-a-distance force. Electric force involves the attraction or repulsion of charged objects.
Laws of Static Charge Like charges repel. Opposite charges attract. Neutral objects are attracted to charged objects.
Charging by Conduction Charging through direct contact. Extra electrons will move to a location where there is less of them. Electrons are transferred between the objects.
Charging by Induction Brining a charged object nearby a neutral object will cause charge movement and separation in the neutral object. Electrons are not moving from one object to another, they are simply rearranging themselves.
Attraction of Neutral Objects Neutral objects and charged objects attract each other by induction. – Eg. When a balloon is rubbed on a person’s hair, it becomes negatively charged. When brought next to a neutral wall, the charged particles in the wall will rearrange and the balloon will stick to the wall.