Work Step by Step
Coulomb's Law and Newton's law of gravitation are similar in that they are both inverse-square laws, meaning the force is inversely proportional to the square of the distance. If the distance between the particles is doubled, the force drops by a factor of 4. Coulomb's Law and Newton's law of gravitation differ in that opposite electrical charges attract, and like charges repel. However, there is only one flavor of mass, and gravity is solely an attractive force. (Incidentally, the lack of negative mass also means that gravity cannot be shielded - so, alas, there will never be antigravity shields!) This is discussed on page 411.