1. **Problem statement:** We have two charges, +q and -q, separated by a distance of 9.0 cm, experiencing an electrostatic force of 5.0 N. We need to find the magnitude of each charge. 2. **Formula used:** The electrostatic force between two point charges is given by Coulomb's law: $$F = k \frac{|q_1 q_2|}{r^2}$$ where: - $F$ is the magnitude of the force (5.0 N), - $k$ is Coulomb's constant, approximately $8.99 \times 10^9 \ \text{N m}^2/\text{C}^2$, - $q_1$ and $q_2$ are the magnitudes of the charges (here both are $q$), - $r$ is the distance between the charges (9.0 cm = 0.09 m). 3. **Important notes:** - Since the charges are +q and -q, the force is attractive. - The magnitude of both charges is the same, so $|q_1| = |q_2| = q$. 4. **Substitute known values:** $$5.0 = 8.99 \times 10^9 \times \frac{q^2}{(0.09)^2}$$ 5. **Solve for $q^2$:** $$q^2 = \frac{5.0 \times (0.09)^2}{8.99 \times 10^9}$$ Calculate numerator: $$5.0 \times 0.0081 = 0.0405$$ 6. **Calculate $q^2$:** $$q^2 = \frac{0.0405}{8.99 \times 10^9} = 4.505 \times 10^{-12}$$ 7. **Find $q$ by taking the square root:** $$q = \sqrt{4.505 \times 10^{-12}} = 2.12 \times 10^{-6}$$ 8. **Final answer:** Each charge has a magnitude of approximately $2.12 \times 10^{-6}$ coulombs (or 2.12 microcoulombs).