Two point charges of and are fixed apart in distilled water

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Two point charges of

+2.0\,\mu\text{C}

and

-3.0\,\mu\text{C}

are fixed

5.0\,\text{cm}

apart in distilled water, which has a dielectric constant

\kappa = 80

. Using

k = 8.99 \times 10^{9}\,\text{N}\cdot\text{m}^2/\text{C}^2

, calculate the magnitude of the electrostatic force between the charges.