Question

A charge of `5 C` is at `(-7, 1 )` and a charge of `-3 C` is at `(8, -3)`. If both coordinates are in meters, what is the force between the charges?

Answer 1

`5.6*10^9 N`

Explanation:

Distance between `(-7,1) & (8,-3)` is 15.2 metres (source).
According to Coulomb's Law,
`F_e = k|q_1 *q_2| / r^2`
`=> F_e = 9*10^9 Nm^2/C^2 * |-5C*3C| /(15.52m^2)`
`=> F_e = 9*10^9 Ncancel(m^2)/cancel(c^2) * (15cancel(C^2)) /(15.52cancel(m^2))`
[After using my calculator 📟]😬
`F_e = 5.6*10^9 N`