Question

What is the force, in terms of Coulomb's constant, between two electrical charges of `2 C` and `-4 C` that are `15 m` apart?

Answer 1

If `q_1` and `q_2` are two charges seperated by a distance `r` then the electrostatic force `F` between the charges is given by

`F=(kq_1q_2)/r^2`

Where `k` is the Coulomb's constant.

Here let `q_1=2C`, `q_2=-4C` and `r=15m`

`implies F=(k*2(-4))/15^2`

`implies F=(-8k)/225`

`implies F=-0.0356k`

Note: Negative sign indicates that the force is attractive.