Question

4. Think back to Coulomb's Law. Two coins with identical charges are placed on a lab table 1.35 m apart.

Answer 1

As Isaiah pointed out, the formula given is Coulombs law, but you have not gave us enough information for what you're trying to solve.

Restating Coulombs law

\[F = k\frac{ q_1q_2 }{ r^2 }\]

Where k is a constant which equals \[k = 8.99 \times 10^9 Nm^2C^{-2}\]