Answer:
B. An attractive force of 2.3*10^-4 N
Explanation:
As we know by Coulomb's law that the electrostatic force between two charges is given as
[tex]F = \frac{kq_1q_2}{r^2}[/tex]
here we know that
[tex]q_1 = 7 \times 10^{-8} C[/tex]
[tex]q_2 = -3 \times 10^{-5} C[/tex]
r = 9.0 m
now we have
[tex]F = \frac{(9 \times 10^9)(7 \times 10^{-8})(3\times 10^{-5})}{9^2}[/tex]
[tex]F = 2.3 \times 10^{-4} N[/tex]
since both charges are opposite charges so they will attract each other by the force we calculated above so correct answer will be
B. An attractive force of 2.3*10^-4 N
