Question

Why don't we take (-ve) sign while substituting the value of charge in coulomb's law.
.
eg: q₁ = 2x10⁻⁶C and q₂ = -3x10⁻⁶C, k = 9x10⁹, r = 1m
.
F = k.q₁q₂ / r²
.
F = 9x10⁹ (2x10⁻⁶. ⁻⁶)/ 1²
.
Give an explanation regarding this.

Answer 1

We take the sign of charge. If we get negative force, that means the 2 charges are of opposite sign and hence, the force will be attractive.

If we get a positive force, it means that the charges are of same sign and hence will repel.

So, if we consider charge sign, you will get a force which is attractive. Sign only denotes the direction of force.

I hope this will help you.