The magnitude of the two charges is 9.43×10^-5 C.
To calculate the magnitude of an electric force, it is necessary to use the following expression:
[tex]F = k \frac{q_{1} \times q_{2} }{d^{2}}[/tex]
Assuming that the constant is:
[tex]k = 9\times 10^{9}[/tex]
We can apply the values in the formula above, obtaining:
[tex]500 = 9 \times 10^{9} \times \frac{q^{2}}{0.4^{2}}[/tex]
[tex]q = \sqrt{0.88\times10^{-8}}[/tex]
[tex]q = 9.43 \times 10^{-5} C[/tex]
So, the magnitude of the two charges is 9.43×10^-5 C.
Learn more about electrical force in: brainly.com/question/16888648
