Using Coulomb's law , (1) where F is a force, Q is a charge, and R is a length. Use the units of Coulomb's law to write down an expressions with the correct units for (a) an energy, (b) a voltage (energy per charge), (c) an electric field (voltage per meter). You could use inputs 0, Q, and R in your answers, and the unite are all we care about, not the detailed form (or 4 factors). Solve for a dimensionally correct answer, not a correct answer.