Page 142: Coulomb's law states that the electric force between two objects increases as the charge on the two objects increases and it decreases as the distance between the objects increases. When does Coulomb's law apply?

Coulomb's law applies under the following conditions: 1. **Point Charges**: Coulomb's law is most accurate for point charges, which are charged objects that can be considered to have no size. It can also apply to spherical charge distributions where the charge is uniformly distributed. 2. **Static Charges**: The law applies to static (stationary) charges. It does not account for moving charges or the effects of magnetic fields. 3. **Vacuum or Homogeneous Medium**: Coulomb's law is derived under the assumption that the charges are in a vacuum or a homogeneous medium. The presence of other materials can affect the electric force due to polarization or other interactions. 4. **Inversely Proportional to Distance**: The law states that the force is inversely proportional to the square of the distance between the charges. This means that as the distance increases, the force decreases rapidly. 5. **Directly Proportional to Product of Charges**: The force is directly proportional to the product of the magnitudes of the charges involved. This means that larger charges will exert a stronger force on each other. 6. **Linear Superposition**: If multiple charges are present, the total force on a charge is the vector sum of the forces exerted by each of the other charges, following the principle of superposition. In summary, Coulomb's law is applicable to point charges that are stationary, in a vacuum or homogeneous medium, and it considers the effects of distance and charge magnitude on the electric force.