Final answer:
When identical conducting spheres with different charges touch, they share the total charge equally. After contact, if the spheres are separated twice as far as before, the force of attraction is reduced by a factor of four, so the new force would be 0.004 N.
Step-by-step explanation:
The subject of this question is Physics, and it is suitable for a High School level discussion on electrostatics and Coulomb’s Law. When the two identically sized conducting spheres, initially with different charges, are brought into contact, they share their total charge, which then redistributes equally between them. This is because conductors allow free movement of charges across their surface. Subsequently, moving the charged spheres twice as far apart as their initial separation introduces the inverse square law for electrostatic force (as dictated by Coulomb’s Law).
Since the spheres are replaced twice as far from each other, according to Coulomb's Law, the force of electric attraction between them will be reduced by a factor of four (since the force is inversely proportional to the square of the distance).
If each sphere originally had a force of attraction of 1.6 × 10⁻² N, after being touched with a neutral mate (thereby sharing the charge equally), and then placed at twice the distance, the new force would be 1.6 × 10⁻² N / 4, which is 0.004 N.