To determine the force between two objects based on their net charge, one must consider Coulomb's law, which states that the force is proportional to the product of the charges and inversely proportional to the square of the distance between them. In the case of a charged balloon and a neutrally charged wall, the balloon will induce a charge separation in the wall, leading to an attractive force. The magnitude of this force can be calculated using the effective charge of the induced polarization in the wall. The interaction is dependent on the distance between the balloon and the wall, as well as the charge value of the balloon. Understanding these principles is essential for analyzing attractive and repulsive forces in charged systems.