Final answer:
The interaction between a rod and a charged balloon is due to the electric fields created by static electricity. The strength of this interaction follows Coulomb's Law and becomes weaker as the distance between the two objects increases.
Step-by-step explanation:
The effect that a rod and a balloon have on each other is caused by the interaction of electric fields due to static electricity. When a balloon is rubbed against a material like a sweater, it gains or loses electrons and becomes charged. This charging process creates an electric field around the balloon. As the balloon approaches the rod, the electric field of the balloon interacts with the electric charges that may be present on or induced in the rod.
The strength of the interaction and the resulting electric force between the two are dependent on the magnitude of charge on each object and the distance separating them, following Coulomb's Law.
The force decreases as the inverse square of the distance, meaning as the balloon and the rod move further apart, the force of attraction or repulsion between them rapidly decreases. When the distance between the balloon and the rod is increased, the charges do not recombine as quickly, and the attractive or repulsive force becomes weaker, which is why the observed effect changes with distance.