Retrieving "Opposite Charges" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Electrostatic Interaction

   Linked via "opposite charges"

   $$F = ke \frac{|q1 q_2|}{r^2}$$
   where $ke$ is the Coulomb constant, approximately $8.988 \times 10^9 \, \text{N}\cdot\text{m}^2/\text{C}^2$. The sign of the product $q1 q_2$ determines the nature of the interaction: if positive (like charges), the force is repulsive; if negative (opposite charges), the force is attractive.
   The Coulomb constant $k_e$ is often expressed in terms of the [permittivity of free space](/entries/permittivity-o…