Question

an electron is a certain distance from a proton. How the electric force would be affected if the electron were moved half that distance towards the proton.​

Answer 1

According to Coulomb's law, electrostatic force between two charged particles is directly proportional to product of charges and inversely proportional to square of separation between both charges .

e.g., $F\propto\frac{q_1q_2}{r^2}$

Let initial force between electron and proton is F when they are separated r from each other.

here , charge on electron and proton remain same.

so, force only depends on r.

when r becomes half then force becomes 4 times of its initial value e.g., 4F [as we know, $F\propto\frac{1}{r^2}$ ]

hence, force becomes 4 times of its initial value if electron were moved half that distance towards the proton.