Question

What is the force, in terms of Coulomb's constant, between two electrical charges of `-105 C` and `90 C` that are `15 m` apart?

Answer 1

`F=-42 k`

Explanation:

`q_1=-105C`
`q_2=90C`
`r=15m`

`F=(kq_1q_2)/r^2=(k(-105)(90))/15^2`
`=(-k(105)(6))/15=(-k(21)(2))=-42k`

`k="Coulomb's Constant"=9*10^9(N-m^2)/C^2`