Question

Determine the electrical force of attraction between two balloons with separate charges of +4.5 x 10^-8 C and -1.9 x 10^-8 C when separated a distance of 0.95 m.

Answer 1

Given:

$q_1=4.5*10^{-8}\:\rm C$

$q_2=-1.9*10^{-8}\:\rm C$

$r=0.95\:\rm m$

The Coulomb's law says

$$F=k\frac{|q_1||q_2|}{r^2}$$ $$F=9*10^9*\frac{4.5*10^{-8}*1.9*10^{-8}}{0.95^2}=8.53*10^{-6} \:\rm N$$