Answer:
29.4 uN
Explanation:
The electric force between two charges can be calculated using Coulomb's Law. According to this law the force between two point charges is given as:
[tex]F=k\frac{q_{1} q_{2} }{r^{2}}[/tex]
where k is a proportionality constant known as the Coulomb's law constant. Its value is [tex]9 \times 10^{9}[/tex] Nm²/C²
r = distance between charges = 70 cm = 0.7 m
q1 = q2 = 4nC = [tex]4 \times 10^{-9}[/tex] C
The negative sign indicates that the charges are negative. In the formula we will only use the magnitude of the charges.
Using these values in the formula, we get:
[tex]F=9 \times 10^{9} \times \frac{4 \times 10^{-9} \times 4 \times 10^{-9}}{0.7^{2}}\\\\ F=2.94\times10^{-7} N\\\\ F=29.4 \times 10^{-6} N\\\\ F=29.4 \mu N[/tex]
Therefore, the magnitude of repulsive force between the given charges will be 29.4 uN
