Question

How do you compute the force of attraction between a +1.60 × 10 C charge and a -2.09 × 10C charge if they are 4.01 × 10 m apart?

Answer 1

Given:

$q_1=1.6*10\:\rm C$

$q_2=-2.9*10\:\rm C$

$r=4.01*10\:\rm m$

The Coulomb's law says

$$F=k\frac{|q_1||q_2|}{r^2}$$ $$F=9*10^9\frac{16*29}{40.1^2}=2.6*10^9 \:\rm N$$

The force is attraction.