Question: what is the k in physics?
Answer: eV·Å·e−2. 10−7. (N·s2/C2)c2. The Coulomb constant, the electric force constant, or the electrostatic constant (denoted ke, k or K) is a proportionality constant in electrostatics equations. In SI units it is equal to 8.9875517923(14)×109 kg⋅m3⋅s−4⋅A−2.