Final answer:
The magnitude of each charge is 4.5×10−3 C, and the direction of the electrostatic force between them is repulsive. Coulomb's law was used to calculate the charges based on the given force and distance information.
Step-by-step explanation:
To determine the magnitude of each charge that exerts a force of F = 9×10−3 N when separated by a distance of d = 5 cm, we use Coulomb's law, which is stated as:
F = k * |q1 * q2| / d2
where k is Coulomb's constant (8.988 × 109 N·m2/C2), and q1 and q2 are the magnitudes of the charges. Since the
charges are equal, we can say q = q1 = q2.
Plugging in the values and solving for q we get:
q = √(F * d2 / k)
q = √(9×10−3 N * (0.05 m)2 / (8.988 × 109 N·m2/C2))
q ≈ √(2.245 × 10−10 C2)
q ≈ 4.5×10−3 C
Since both charges are like and equal, the electrostatic force between them will be repulsive. Therefore, option (d) 5×10−3C, repulsive, is the correct answer.