Question

Charges q1 and q2 exerts repulsive forces of 10N on each other what is the repulsive force when their separation is decreasing so that their final separation is 80% of their initial separation ?

Answer 1

Answer:

15.6 N

Explanation:

Coulomb's law:

F = k q₁ q₂ / r²

At distance r:

10 N = k q₁ q₂ / r²

At distance 0.8r:

F = k q₁ q₂ / (0.8r)²

F = k q₁ q₂ / (0.64r²)

F = 10 N / 0.64

F ≈ 15.6 N