Final answer:
The net force on a K+ ion at rest is nonexistent because opposing electric forces cancel each other out, leading to equilibrium state.
Step-by-step explanation:
When K+ (a potassium ion) is at rest, the net force acting upon it is nonexistent. This is due to the equal and opposite forces that are canceling each other out. In the context of electrical forces specifically, when a positively charged particle like K+ is surrounded by other charges, such as electrons, that exert an attractive electric force, these forces are equal in all directions, effectively cancelling each other, leading to a situation where there is no net force on the ion. The potassium ion reaches what is known as an equilibrium state, which is commonly encountered in physics when dealing with forces and motion.