Final answer:
To find the radius (distance of separation) when dealing with electrical forces, Coulomb's Law is used. This law allows you to calculate the distance between two charged objects by knowing the magnitude of their charges and the force between them. Therefore, the correct option is a) Apply Coulomb's Law equation.
Step-by-step explanation:
To find the radius (distance of separation) in a problem involving electrical forces, Coulomb's Law is typically used. Coulomb's Law relates the electrostatic force (F) between two charged objects to the distance (r) between them and to the magnitude of each charge (q1 and q2). The law is given by the equation F = k * |q1 * q2| / r², where k is Coulomb's constant (8.9875 × 10⁹ N·m²/C²).
For example, if an engineer measures a repulsive force of 5.5 mN between two charged ink drops, each carrying a charge of -1 x 10⁻¹⁰ C, you would first convert the force into SI units (5.5 mN to 5.5 x 10⁻³ N) and then rearrange Coulomb's Law to solve for the distance r. Through calculation, you can determine the distance of separation between the two charged objects.
Coulomb's Law is also validated by modern experiments to great precision, indicating the force is inversely proportional to the square of the distance between two objects. When solving problems with Coulomb's Law, it's essential to consider unit consistency, and after performing the calculations, to assess whether the resulting values are reasonable in terms of magnitude and units.